taxonID	type	description	language	source
038E8789773C7F1481AFA7F1FC2AFC2D.taxon	description	Figs. 2 a, b, 14 c, 15 a, 18 a, 21 a, 26 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789773C7F1481AFA7F1FC2AFC2D.taxon	description	Head: transverse in both sexes; ratio length / width in males 0.715 (range 0.64 – 0.83), in females 0.825 (range 0.77 – 0.86). Dorsal surface with sulcate longitudinal midline visible from anterior margin of head to level of posterior margin of eyes; front with distinct and broad fovea between antennal insertions and a little posteriorly where it becomes narrower. Eyes slightly longer than 0.5 times the cephalic lateral length and slightly protruding. Antennomeres 2 – 3 almost with same length, 4 – 5 slightly elongate, 6 nearly as long as wide, 7 – 10 slightly transverse. Males with mandibles longer than head (ratio 1.3, range 1.00 – 1.48); females with mandibles slightly shorter than head (ratio 0.94, range 0.81 – 1.09); mandibles with two (basal and middle) clearly separated teeth; mandibular channel well developed, external margin well separated from internal margin; internal margin carinate until near the level of middle tooth, then extending higher as impressed line. Apical palpomere of maxillary and labial palpi nearly 1.5 times longer than preapical palpomere. Ventral surface with microsculpture less visible than on dorsal surface. Head wider than pronotum, both in males (ratio 1.21, range 1.14 – 1.28) and females (ratio 1.07, range 1.03 – 1.11). Thorax: pronotum with five punctures in each dorsal row; slightly longer than wide, both in males (ratio 1.11, range 1.03 – 1.15) and females (ratio 1.16, range 1.03 – 1.22); almost as wide at anterior corners as at posterior corners in both sexes (ratio in males 1.05, range 1.04 – 1.10, in females 1.02, range 1.00 – 1.06). Scutellum with punctures denser than on elytra; elytra with sparse and fine punctures, with pale setae. Prosternum with an elevated area before anterior margin. Intercoxal process of mesoventrite with shape of acute shield; transverse discal ridge very widely U-shaped or V-shaped, not meeting margin of intercoxal process laterally. Males with profemora with external row of spines, starting near basal third and not reaching the apex, spines do not overlap with those of internal apex, which are among three to five of moderate size. Hind legs of males with trochanter modified like a hook, in large specimens slightly less than 1 / 2 the length of metafemur, in smaller specimens as long as 1 / 4 the length of metafemur and its apex is less convex; femur curved at level of its overlap with hook; tibia a little curved in apical third. Tarsomeres very slender and scarcely flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina, followed by a slightly visible slightly depressed area, with smooth microsculpture and some wide-superficial punctures; remaining area of tergites 1 – 3 and following tergites only with fine punctures. Visible sternites 1 – 2 with wide-superficial punctures denser than on tergites, covering more than anterior half, combined with fine punctures; sternites 3 – 4 with sparse wide-superficial punctures covering less than anterior half; sternite 5 with sparse wide-superficial and fine punctures; sternite 6 only with fine punctures. Male pregenital sternite evenly rounded at posterior margin (Fig. 15 a). Male genital sternite very elongate (3.4 times longer than wide), more or less symmetrical, anterior portion occupies 42 % and posterior portion occupies 48 % of its length, apical emargination very deep (Fig. 18 a). Male abdominal styli black, moderately widened at apex (Fig. 14 c), although less wide and robust than in B. trochanterinus. Aedeagus: length 1.4 mm; elongate shape; apex slightly acute, somewhat rounded; in ventral view, basal half slightly wider than apical half; in lateral view the greater width of basal half is more noticeable; internal sac visible (Fig. 21 a). Variability. In addition to the variation in the measurements and ratios included in the description, only differences related to the sex and size of the specimens were observed. Taxonomic comments. Belonuchus alternans is very similar to B. magnistylus, from which it is distinguished almost exclusively by the fact that the latter species has the male abdominal styli notably wider, pregenital sternite with the posterior margin emarginate and a different shape of the aedeagus. In B. alternans the abdominal styli of males are only moderately wider, the pregenital sternite is evenly rounded at posterior margin and the aedeagus is less wide at base. Additionally, B. alternans could be confused with B. trochanterinus and B. confusus for having a similar coloration pattern and size, as well as the wider male abdominal styli. It can be distinguished because B. alternans has the last three visible abdominal segments black (except the anterior border of the fourth visible segment that is reddish), male abdominal styli moderately wider and the genital sternite and the aedeagus of different shape in comparison with the other two species, which have only the last two visible abdominal segments black (except the anterior border of fifth visible segment that is reddish) and the male abdominal styli notably wider. The syntypes of this species were not studied in person, but we analyzed some photos of these specimens (Fig. 2 a; NHM, shared by M. Chani Posse) which, together with the original description (Sharp, 1885), allowed us to identify this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789773C7F1481AFA7F1FC2AFC2D.taxon	materials_examined	Material examined (448 males, 431 females): Mexico: Hidalgo: “ Acaxochitlán, Tlazintla, bosque encinopino, 2149 m, N 20 ° 09 ’ 7.96 ”, W 98 ° 11 ’ 1.83 ”, NTP- 80 (calamar), (without data) J. Islas col. ” (8, CC-UAEH). “ Chapulhuacán, El Infiernillo, selva mediana, 500 - 850 m, N 21 ° 7.54 ’, W 98 ° 58.001 ’, hojarasca cernida, 20 - IV- 2013, J. Márquez col. ” (1, CC-UAEH). “ Chapulhuacán, Tamaulipas, bosque mesófilo de montaña, 1133 m, N 21 ° 10.036 ’, W 98 ° 55.984 ’, NTP- 80 (calamar) # 3, 30 - III a 06 - IV- 2005, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (2, CC-UAEH). Same data, except: “ N 21 ° 09.9 ’ 7.9 ”, W 98 ° 55.8 ’ 04.0 ”, NTP- 80 (calamar) # 3, 12 a 26 - III- 2011. J. Márquez col. ” (2, CC-UAEH). Same data, except: “ NTP- 80 # 7 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 6 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 4 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (2, CC-UAEH). Same data, except: “ NTP- 80 # 5 (calamar) ” (2, CC-UAEH). Same data, except: “ NTP- 80 # 8 (calamar) ” (2, CC-UAEH). Same data, except: “ NTP- 80 # 2 (calamar) ” (1, CC- UAEH). Same data, except: “ Coprotrampa ” (4, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 5 (calamar), 28 - VIII a 11 - IX- 2011 ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 9 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (1, CC-UAEH). “ Huehuetla, Rio Blanco, bosque tropical perennifolio, 588 m, UTM (WG- 384), 145 94809 E, 2257303 N, NTP- 80 (calamar), 1 al 30 - V- 2010, C. Berriozábal col. ” (9, CC-UAEH). “ Jacala de Ledezma, 1 km E de El Durazno, bosque pino-encino- Junniperus, 1694 m, N 20 ° 3 ’ 11.1 ”, W 99 ° 1 ’ 20 ”, NTP- 80 (calamar), 8 al 16 - III- 2008, J. Márquez y J. Asiain cols. ” (4, CC-UAEH). “ Jacala de Ledezma, 3 km antes de Las Moras, bosque mesófilo de montaña, 1678 m, trampa de intercepción de vuelo, 3 - XII- 2008, J. Márquez col. “ (17, CC-UAEH). “ Juárez, bosque mesófilo perturbado, 1970 m, N 20 ° 47 ’ 9.6 ”, W 98 ° 49 ’ 5.2 ”, trampa de intercepción de vuelo # 2, 7 al 14 - III- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (3, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 3 (calamar) ” (4, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (1, CC-UAEH). “ La Misión, Lomas del Pericón, bosque mesófilo de montaña, 1377 m, N 21 ° 60 ’ 46.0 ”, W 99 ° 6.0 ’ 15.6 ”, NTP- 80 (calamar), 8 al 16 - III- 2008, J. Márquez y J. Asiain cols. ” (38, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3, 26 - VIII a 9 - IX- 2011, J. Márquez col. ” (1, CC-UAEH). “ La Misión, bosque mesófilo de montaña, 1337 m, N 21 ° 06 ’ 202 ”, W 99 ° 06 ’ 291 ”, NTP- 80 (calamar) # 1, 29 - III al 05 - IV- 2009, J, Márquez, M. Rivera, M. Torres, M. Vargas y J. Sánchez cols. ” (3, CC-UAEH). “ La Misión, Los Naranjos, Palo Hueco, bosque mesófilo de montaña, 1276 m, N 21 ° 08 ’ 06 ”, W 99 ° 05 ’ 02 ”, NTP- 80 (calamar) # 6, 10 a 24 - III- 2011, J. Márquez col. ” (2, CC-UAEH). “ La Misión, Palo Hueco, 1.5 km al NE de Puerto de Naranjos, bosque mesófilo de montaña, 1197 m, N 21 ° 08 ’ 21 ”, W 99 ° 05 ’ 4.6 ”, coprotrampa, 10 a 24 - III- 2011, J. Márquez col. ” (3, CC-UAEH). “ La Misión, camino al río Moctezuma, N 21 ° 8 ’ 30.6 ”, W 99 ° 5 ’ 49.1 ”, bosque tropical subcaducifolio, trampa de intercepción de vuelo, 23 - VI a 5 - VII- 2017, J. Márquez y A. Lora cols. ” (7, CC-UAEH). “ Molango, Acuatitlán, bosque mesófilo de montaña, 1715 m, N 20 ° 45 ’ 38.4 ”, W 88 ° 42 ’ 50.7 ”, en tronco con hongos, 10 - IV- 2008, J. Márquez, J. Bueno y M. García cols. ” (2, CC-UAEH). “ Molango, Acuatitlán, bosque mesófilo de montaña, 1715 m, N 20 ° 45 ’ 38.4 ”, W 88 ° 42 ’ 50.7 ”, NTP- 80 (calamar) # 2, 15 a 29 - IV- 2011, J. Márquez col. ” (27, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (25, CC-UAEH). Same data, except: “ NTP- 80 # 4 (calamar) ” (22, CC-UAEH). Same data, except: “ NTP- 80 # 7 (calamar) ” (19, CC-UAEH). Same data, except: “ NTP- 80 # 3 (calamar) ” (6, CC-UAEH). Same data, except: “ NTP- 80 # 6 (calamar) ” (10, CC- UAEH). Same data, except: “ NTP- 80 # 5 (calamar) ” (13, CC-UAEH). Same data, except: “ NTP- 80 # 8 (calamar) ” (4, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (2, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (3, CC-UAEH). Same data, except: “ NTP- 80 # 3 (calamar), 30 - IX a 21 - X- 2011 ” (1, CC-UAEH). Same data, except: “ hojarasca cernida, 12 - IV- 2011 ” (1, CC-UAEH). “ Nicolás Flores, cerca de Villahermosa, bosque de encino, 2221 m, N 20 ° 43 ’ 49.7 ”, W 99 ° 07 ’ 35.2 ”, NTP- 80 # 3 (calamar), 21 a 28 - II- 2009, J. Márquez, M. Rivero, M. Torres y J. Sánchez cols. ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2 ” (4, CC-UAEH). “ Pacula, camino al Membrillar del Fraile, río Moctezuma, N 99 ° 23´28 ”, W 21 ° 5´26.8 ”, 903 m, vegetación riparia, NTP- 80 (calamar), 19 - I a 25 - II- 2010, J. Islas col. “ (7, CC-UAEH). “ Pacula, Puerto Grande, bosque de encino, 2109 m, N 20 ° 53.850 ’, W 99 ° 19.562 ’, NTP- 80 # 3 (calamar), 28 - III al 04 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (2, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 2 (calamar) ” (1, CC-UAEH). “ Tenango de Doria, El Potrero, bosque mesófilo de montaña, 2185 m, N 20 ° 18 ’ 49.5 ”, W 98 ° 13 ’ 43.3 ”, NTP- 80 # 1 (calamar), 18 a 25 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Tenango de Doria, camino a La Viejita, bosque mesófilo de montaña, 1647 m, N 20 ° 19.0 ’ 37.9 ”, W 98 ° 14 ’ 39.7 ”, NTP- 80 # 2 (calamar), 29 - III a 12 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (2, CC-UAEH). Same data, except: “ NTP- 80 # 7 (calamar) ” (3, CC-UAEH). Same data, except: “ NTP- 80 # 5 (calamar) ” (4, CC-UAEH). Same data, except: “ NTP- 80 # 3 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 3 (calamar), 1 a 15 - IX- 2011. ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 4 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (3, CC-UAEH). Same data, except: “ NTP- 80 # 6 (calamar) ” (3, CC-UAEH). Same data, except: “ NTP- 80 # 5 (calamar) ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2, 5 a 12 - IV- 2013, N. Gutiérrez col. “ (2, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (3, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1, 11 a 16 - VI- 2013 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar), 12 - VIII- 2010, C. Cornejo col. ” (9, CC-UAEH). “ Tepehuacán de Guerrero, Chilijapa, bosque mesófilo de montaña perturbado, 1323 m, N 21 ° 1.91 ’, W 98 ° 51.812 ’, NTP- 80 (calamar), 22 a 24 - IV- 2004, J. Asiain, J. Islas, J. Márquez cols. ” (1, CC-UAEH). “ Tepehuacán de Guerrero, Chilijapa, bosque mesófilo de montaña, 1401 m, N 21 ° 1.2 ’ 5.1 ”, W 98 ° 51.8 ’ 2.1 ”, NTP- 80 (calamar) # 2, 11 a 25 - III- 2011, J. Márquez col. ” (13, CC-UAEH). Same data, except: “ NTP- 80 # 3 (calamar) ” (7, CC- UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 9 (cal.) ” (3, CC-UAEH). Same data, except: “ NTP- 80 # 6 (calamar) ” (6, CC-UAEH). Same data, except: “ NTP- 80 # 8 (calamar) ” (11, CC-UAEH). Same data, except: “ NTP- 80 # 7 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 5 (calamar) ” (7, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2. ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1. ” (5, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1, 27 - VIII a 10 - IX- 2011 ” (2, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2. ” (4, CC- UAEH). Same data, except: “ trampa de intercepción de vuelo # 3. ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 1 ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 2 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 10 (calamar) ” (4, CC-UAEH). Same data, except: “ coprotrampa, 12 a 26 - III- 2011. ” (2, CC-UAEH). Same data, except: “ Coprotrampa ” (12, CC-UAEH). Same data, except: “ NTP- 80 (calamar) ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 4 ” (22, CC-UAEH). Same data, except: “ en hojarasca cernida, 19 - IV- 2013 ” (1, CC-UAEH). “ Tepehuacán de Guerrero, Otongo, 650 m, 2 marzo 1981, ex carrion trap, M. A. Morón ” (1, IEXA). Same data, except: “ 1120 m, may-june, 1981 ” (1, IEXA). “ Tianguistengo, camino a Santa Mónica, bosque mesófilo de montaña 1868 m, N 20 ° 43 ’ 5.4 ”, W 98 ° 39 ’ 40.3 ”, trampa de intercepción de vuelo, 7 a 13 - VI- 2009, J. Sánchez, M. Rivero, M. Vargas y J. Márquez cols. ” (3, CC-UAEH). “ Tepehuacán de Guerrero, San Juan Ahuehueco, selva mediana, 1016 m, N 21 ° 01.766 ’, W 98 ° 54.285 ’, NTP- 80 (calamar) # 1, 29 - III al 05 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Tlahuiltepa, 500 m al sureste de Tlaxcantitla, N 20 ° 51 ’ 41.03 ”, W 98 ° 53 ’ 17.03 ”, NTP- 80 # 1, 17 al 14 - III- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y M. Sánchez cols. ” (6, CC-UAEH). “ Tlanchinol, bosque mesófilo de montaña, en necrotrampa temporal, 15 al 19 - V- 1996, J. Márquez col. ” (6, MAAS). Same data, except: “ NTP- 80 (cal.), 29 - IV a 29 - V de 1995, A. Soria col. ” (2, MAAS). “ 3 km N de Tlanchinol, bosque mesófilo de montaña, 1450 m, N 21 ° 1.328 ’, W 98 ° 38.77 ’, en hojarasca, 1 - V- 2003, J. Asiain y J. Márquez cols. ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) 16 - IV a 1 - V- 2003, J. Asiain y J. Márquez cols. ” (6, CC-UAEH). “ Tlanchinol camino a Apantlazol, El Pozo, bosque mesófilo de montaña, 1391 m, N 20 ° 59 ’ 6.73 ”, W 98 ° 37 ’ 39.86 ”, NTP- 80 (calamar) # 6, 1 a 22 - X- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 4 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (1, CC- UAEH). Same data, except: “ trampa de intercepción de vuelo # 2 ” (2, CC-UAEH). Same data, except: “ NTP- 80 # 2 (calamar), 16 a 30 - IV- 2011. ” (8, CC-UAEH). Same data, except: “ NTP- 80 # 4 (calamar) ” (7, CC-UAEH). Same data, except: “ NTP- 80 # 6 (calamar) ” (13, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 5 ” (8, CC-UAEH). Same data, excep: “ NTP- 80 (calamar) # 1 ” (10, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2 ” (8, CC- UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (27, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (9, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2 ” (6, CC-UAEH). “ Tlanchinol, La Cabaña, bosque mesófilo de montaña, 1462 m, N 21 ° 01.333 ’, W 98 ° 38.650 ’, trampa de intercepción de vuelo # 4, 15 a 22 - IV- 2006, C. Ortiz y M. C. Pedraza cols. ” (1, CC-UAEH). Same data, except: “ 1478 m, N 21 ° 0.343 ’, W 98 ° 38.600 ’, trampa de intercepción de vuelo # 5, 16 a 23 - VII- 2005, M. C. Pedraza, E. Pedraza y C. Ortiz cols. ” (1, CC-UAEH). Same data, except: “ 1485 m, N 21 ° 1.357 ’, W 98 ° 38.556 ’, trampa de intercepción de vuelo # 3, 17 a 24 - IX- 2005 ” (1, CC-UAEH). Same data, except: “ 1477 m, N 21 ° 01 ’ 15.94 ”, W 98 ° 38 ’ 40.14 ”, en hojarasca cernida, 8 - VI- 2007, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). Same data, except: “ 1462 m, N 21 ° 1.338 ’, W 98 ° 650 ’, trampa de intercepción de vuelo, 13 al 20 - V- 2006, C. Ortiz y M. C. Pedraza cols. ” (1, CC-UAEH). Same data, except: “ 1478 m, N 21 ° 01.343 ’, W 98 ° 650 ’ ” (1, CC-UAEH). “ Tlanchinol, cerca de la Cabaña, bosque mesófilo de montaña, 1450 m, N 21 ° 01.328 ’, W 98 ° 38.770 ’, en hongos de repisa de troncos, 16 - IV- 2003, J. Márquez y J. Asiain cols. ” (2, CC-UAEH). “ Zacualtipán, camino a Sto. Domingo, bosque mesófilo de montaña, 1830 m, N 20 ° 37.749 ’, W 98 ° 34.851 ’, NTP- 80 (calamar), 30 - VII al 30 - X- 2003, J. Márquez y J. Asiain cols. ” (2, CC-UAEH). “ Zacualtipán camino a Tizapán, bosque mesófilo de montaña, 1790 m, N 20 ° 38 ’ 44.5 ”, W 98 ° 36 ’ 7.2 ”, NTP- 80 (calamar) # 3, 14 a 28 - IV- 2011, J. Márquez col. ” (8, CC-UAEH). Same data, except: “ NTP- 80 # 9 (calamar) ” (9, CC- UAEH). Same data, except: “ NTP- 80 (calamar) # 10 ” (5, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 7 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 8 ” (11, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 1 ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 5 ” (9, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (3, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (6, CC- UAEH). Same data, except: “ trampa de intercepción de vuelo # 3, 20 - IX a 4 - X- 2011 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 10, 20 - IX a 4 - X- 2011 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2 “ (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Minas Viejas, bosque de encino, 1892 m, N 20 ° 55 ’ 5.2 ”, W 99 ° 12 ’ 41.1 ”, NTP- 80 (calamar), 11 - X al 17 - XI- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (4, CC-UAEH). Same data, except: “ coprotrampa, 18 - VIII al 20 - IX- 2007. ” (1, CC-UAEH). Same data, except: “ necrotrampa. ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar), 13 - VII al 18 - VIII- 2007. ” (5, CC-UAEH). “ P. N. Los Mármoles, Zimapán, La Encarnación, bosque de encino, 2412 m, N 20 ° 52 ’ 1 ”, W 99 ° 12 ’ 50.3 ”, Coprotrampa, 30 - V al 23 - IV- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (5, CC-UAEH). Same data, except: “ NTP- 80 (calamar), 23 - VI al 13 - VII- 2007. ” (1, CC-UAEH). ” Zimapán, El Salto a 2 km al E de Durango, bosque de encino, 2099 m, N 20 ° 54.023 ”, W 99 ° 12.933 ’, NTP- 80 # 1 (calamar), 28 - III a 4 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC- UAEH). Same data, except: “ 14 Q 0477632, UTM 2311197, 2155 m, NTP- 80 # 3 (calamar) ” (1, CC-UAEH). “ Zimapán, Minas Viejas, bosque de encino, 1897 m, N 20 ° 55 ’ 23 ”, W 99 ° 12 ’ 28 ”, en excremento vacuno, 20 - X- 2006, J. Asiain y J. Márquez cols. ” (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, bosque de pino-encino, 2444 m, N 20 ° 48 ’ 12.22 ”, W 99 ° 14 ’ 41 ”, coprotrampa, del 22 - VI al 12 - VII- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (2, CC-UAEH). “ Zacualtipán, La Mojonera, N 20 º 37 ’ 59 ”, W 98 º 35 ’ 48 ”, 1886 m, bosque mesófilo de montaña perturbado, NTP- 80 (calamar), 28 - II a 29 - IV- 2004, J. Asiain y J. Márquez cols. ” (1, CC-UAEH). Same data, except: “ mayo-junio, 2004 ” (1, CC-UAEH). “ Zacualtipán, camino a Santo Domingo, N 20 º 37 ’ 44.9 ”, W 98 º 34 ’ 51.06 ”, 1830 m, bosque mesófilo de montaña, NTP- 80 (calamar), 28 - II a 29 - IV- 2004, J. Márquez y J. Asiain cols. ” (11, CC- UAEH). Oaxaca: “ Candelaria Loxicha, Portillo del Rayo, VI- 1990, 950 m, bosque tropical y cafetal, C. Deloya López col. ” (2, IEXA). Puebla: “ Honey, Chila de Juárez, río San Marcos, N 20.277778 °, W 98.213611 °, bosque mesófilo de montaña, 1500 m, NTP- 80 (calamar), 8 a 15 - VIII- 2019, J. D. Silva, R. Ramírez y J. Márquez cols. ” (m 1, CC-UAEH). Same data except: “ en carpotrampa ” (1, CC-UAEH). “ Zacapoaxtla, Ex-hacienda Apulco, cascada La Gloria, N 19 ° 54´2 ”, W 97 ° 37´00 ”, 1,508 m, dentro de cañada bosque mesófilo de montaña rodeado por pinos, trampa de intercepción de vuelo, 18 a 28 - V- 2021, familia Márquez-Asiain cols. ” (14, MAAS). Same data except: “ NTP- 80 (calamar) ” (2, MAAS). Querétaro: “ Pinal de Amoles, cascada del Chuveje, 1350 m, micotrampa, 6 a 10 - VIII- 2002, Q. Santiago y L. Delgado cols. ” (1, IEXA). Veracruz: “ Banderilla, La Martinica, bosque mesófilo de montaña, 1550 m, en hongo Armillariella polymyces # 42, 19 - VI- 2001, L. Delgado col. ” (1, IEXA). “ Córdoba, San Rafael, Calería, Ojo de Agua, selva media subcaducifolia, 1127 m, en lima podrida, 24 - I- 1999, Q. Santiago, J. Asiain y J. Márquez cols. ” (5, MAAS). Same data, except: “ Q. Santiago y J. Márquez cols. ” (1, MAAS). “ Coscomatepec, Tecoac, bosque mesófilo de montaña, 1750 m, NTP- 80 (calamar), 6 - V a 3 - VI- 1995, M. A. Pensado y Q. J. Santiago cols. ” (1, QJSJ). “ Huatusco, Coxcontla, bosque mesófilo de montaña perturbado, 1250 m, NTP- 80 (calamar) # 200, 22 - X a 19 - XI- 1994, M. A. Pensado y Q. Santiago cols. ” (3, QJSJ; 1, MAAS). Same data, except: “ NTP- 80 (calamar) # 419, 17 - XII- 1994 a 14 - I- 1995 ” (1, MAAS; 1, QJSJ). Same data, except: “ NTP- 80 (calamar) # 853, 29 - VII a 26 - VIII- 1995 ” (1, MAAS). Same data, except: “ 6 - V a 3 - VI- 1995 ” (1, QJSJ). Same data, except: “ 3 - VI a 1 - VII- 1995 ” (1, QJSJ). Same data, except: “ 23 - IX a 21 - X- 1995 ” (2, QJSJ). “ Huayacocotla, San Antonio, bosque mesófilo de montaña, 1435 m, N 20 ° 40 ’ 44.6 ”, W 98 ° 23 ’ 06.3 ”, NTP- 80 (calamar) # 2, 01 - V a 28 - V- 2006, F. Ramírez col. ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 1 ” (1, CC-UAEH). “ Huayacocotla, Helechales, bosque mesófilo de montaña, 1936 m, N 20 ° 37.5 ’ 25.0 ”, W 98 ° 27.6 ’ 49 ”, NTP- 80 (calamar) # 3, 19 - III a 2 - IV- 2011, J. Márquez col. ” (17, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 10 ” (29, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 4 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (11, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 7 ” (24, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (8, CC- UAEH). Same data, except: “ NTP- 80 (calamar) # 1 ” (68, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (3, CC-UAEH). “ Xalapa, La Herradura, cafetal y bosque tropical, 1292 m, N 19 ° 31 ’ 07 ”, W 96 ° 53 ’ 45 ”, NTP- 80 (calamar), 26 - XII- 1998 a 26 - I- 1999, Q. Santiago col. ” (4, MAAS). “ Xalapa, Macuiltepetl, Arca Verde, N 19 ° 32´17.72 ”, W 96 ° 55´14.52 ”, 1535 m, pitfall, 2 - VII- 2013, V. Cruz, F. Sandoval y E. Montes de Oca cols. ” (1, QJSJ). Same data, except: “ N 19 ° 32´49.2 ”, W 96 ° 55´12.12 ”, 1538 m, NTP- 80 ” (1, QJSJ). Same data, except: “ N 19 ° 33´7.98 ”, W 96 ° 56´22.62 ”, NTP- 80 ” (1, QJSJ). Same data, except: “ N 19 ° 33´7.86 ”, W 96 ° 56´23.64 ”, 1428 m, coprotrampa ” (2, QJSJ). Same data, except: “ N 19 ° 32´47.46 ”, W 96 ° 55´12.72 ”, 1532 m, NTP- 80 ” (1, QJSJ). Same data, except: “ N 19 ° 32´54.12 ”, W 96 ° 55´10.8 ”, 1546 m, NTP- 80 ” (2, QJSJ). Guatemala: Unknown state: “ Guatemala / M. Cameron. Bequest. B. M. 1955 - 147 ” (m 3, NHM). “ Guatemala, L. Cowcald / M. Cameron. Bequest. B. M. 1955 - 147 / Hesperus. Philonthus trochanterinus Shp. ” (m 1, NHM).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977387F1A81AFA226FBBAFE6D.taxon	description	Figs. 2 c, 12 d, 15 h, 18 b, 21 b, 26 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977387F1A81AFA226FBBAFE6D.taxon	description	Total body length 9.2 mm. Black on head, pronotum, scutellum, anterior half of mesoventrite, posterior 2 / 3 of sixth visible abdominal segment and abdominal styli. Reddish on elytra, legs, posterior half of mesoventrite, metaventrite, 1 – 5 visible abdominal segments and anterior third of 6 visible segment. Prosternum reddish-brown. Genital segment pale reddish. Antennae black, with last antennomere reddish-brown; mandibles, maxillary and labial palpi brown. Head: transverse (ratio length / width 0.92), dorsally slightly convex. Dorsal surface with sulcate longitudinal midline visible at anterior 2 / 3 of head, frontal area slightly foveate. Eyes 0.5 times the cephalic lateral length, not protruding at sides. Antennomere 4 elongate, 5 as long as wide, 6 – 10 transverse. Mandibles shorter than head (ratio 0.91); each with two well separated small teeth (basal and middle); mandibular channel well developed, external margin widely separated from internal margin at base, internal margin carinate until near level of middle tooth, continuing higher as impressed line. Maxillary and labial palpi with the apical palpomere nearly 1.25 times as long as subapical palpomere. Head almost as wide as pronotum (ratio 1.04). Thorax: pronotum with five punctures in left dorsal row and six in right dorsal row; 1.17 times as long as wide; as wide at anterior corners as at posterior corners. Elytra with punctures moderately dense, with fine and pale setae; scutellum with punctures denser than elytra. Prosternum with anterior margin slightly depressed in comparison with central area that is slightly bulky, without carina. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge broadly V-shaped, meeting margin of intercoxal process laterally. Row of spines in external margin of anterior femur with a space without spines before apex, as if one or two spines are missing (Fig. 12 d), basal spines small, initiating slightly before middle part of femur, increasing in size toward space without spines; internal margin with three or four spines of medium size near to apex. Trochanter of posterior legs modified like small hook or like robust spine curved at apex, with length less than 1 / 4 of length of posterior femur; posterior femur weakly curved, or only slightly flattened, at level of its overlap with hook; posterior tibia slightly curved in apical third. Tarsomeres flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina not completely straight; adjacent depressed area very narrow, slightly visible on tergite 3, with sparse wide-superficial punctures; remaining tergites with fine, moderately dense punctures and setae. Abdominal sternites with punctures and setae similar to that on tergites, although with denser wide-superficial punctures on first three sternites. Male pregenital sternite with weak, broadly arcuate emarginate at posterior margin (Fig. 15 h). Male genital sternite short (2.4 times longer than wide), very asymmetrical, anterior portion occupying 31 % and posterior portion 69 % of its length, apical emargination deep (Fig. 18 b). Abdominal styli slender and black at apex. Aedeagus: length 1.25 mm; cone-shaped; apex moderately acute; basal half notably wider than apical half, both in ventral and lateral view, mainly in basal third where it is rounded; internal sac visible (Fig. 21 b). Variability. The holotype is a small specimen in comparison with the average of the remaining analysed specimens: the mandibular length is slightly shorter than the cephalic length, the spines of anterior tibiae less numerous and short, the posterior trochanters modified like a spine or short hook, and the posterior femora and tibiae slightly curved. In larger specimens, the mandibles are longer than the head, the spines of the anterior femora are more numerous and larger, the posterior trochanters are modified like a hook and slightly longer, and the posterior femora and tibiae are more curved. Total body length in males 10.30 mm (range 8.8 – 11.4 mm), in females 10.17 (range 8.7 – 12.1 mm); head a little convex dorsally in large specimens and more convex in small specimens; wider than long in males (ratio 0.795, range 0.72 – 0.90), as in female (ratio 0.836, range 0.87 – 0.96); males with mandibles longer than head (ratio 1.28, range 1.13 – 1.48); females with mandibles shorter than, or almost as long as head (ratio 0.88, range 0.76 – 1.04); males with head wider than pronotum (ratio 1.175, range 1.07 – 1.30), females with head almost as wide as pronotum (ratio 1.05, range 0.93 – 1.28); pronotum slightly longer than wide in males (ratio 1.12, range 1.06 – 1.18) and in females (ratio 1.17, range 1.11 – 1.23); in both sexes, pronotum almost as wide at anterior corners as at posterior corners (ratio in males 1.02, range 1.00 – 1.07, in females 1.01, range 1.00 – 1.06); with five or six punctures in each dorsal row of the pronotum. Taxonomic comments. This species is very similar to B. tepoztecus, it is only possible to distinguish them by the male characters; females of both species from Morelos State (the only place where males of B. tepoztecus are known) are indistinguishable, while females from other localities out of Morelos, based on the geographic distribution of males, can be assigned to B. apiciventris. This latter species has the row of spines of anterior tibiae interrupted before apex, as if one or two spines are missing, trochanters of posterior legs modified like wide hooks, pregenital sternite emarginate at posterior margin and a different shape of the genital sternite and aedeagus; while B. tepoztecus has the rows of spines of anterior tibiae continuous, without interruption until apex, trochanters of posterior legs are modified like hooks, slenderer than in B. apiciventris, pregenital sternite without emargination at posterior margin, and genital sternite and aedeagus are different than in B. apiciventris. Also, B. apiciventris can be confused with B. rufisternus, which is distinguished from B. apiciventris with difficulty. In B. apiciventris the anterior half of the mesoventrite is black, the dorsal rows of pronotum are normally composed of five punctures, the male pregenital sternite is emarginate at posterior margin, and the male genital sternite and aedeagus are different than that of B. rufisternus. While in B. rufisternus, the whole mesoventrite is reddish, the dorsal rows of the pronotum usually include six punctures, the male pregenital sternite without emargination at posterior margin, and has a different male genital sternite and aedeagus.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977387F1A81AFA226FBBAFE6D.taxon	materials_examined	Type material examined: Holotype (male, NHM): “ Philonthus apiciventris Type D. S. Juquila, Mex. Höge (in the plaque with the specimen) / Type / Juquila, Mexico, Hoege / Sharp Coll. 1905 - 313 / B. C. A. Col. I. 2. Philonthus apiciventris Sharp / Sharp Coll. 1905 - 313 / Holotype ”. Additional material examined (67 males, seven females): Mexico: Estado de México: “ 77 M, NE de Temascaltepec, 2150 m, bosque de pino-encino, N 19 ° 5.05 ’, W 100 ° 0.03 ’, sobre hongos Boletaceae, 29 - IX- 1999, A. Newton y M. Thayer cols. ” (m 2, MAAS). Michoacán: “ autopista México - Morelia, km 194, bosque de encino, 218 m, en cadáver de ratón, 20 - IX- 2001, J. Márquez col. ” (m 1, MAAS). Morelos: “ Tlayacapan, San José de los Laureles, camino a Amatlán, bosque de pino, 1930 m, N 18 ° 58 ’ 8 ”, W 99 ° 0.25 ”, NTP- 80 (calamar), 1 a VIII- 1995 (m 1, MAAS). “ Tlayacapan, San José de los Laureles, Loc- 1, N 18 ° 58 ’ 33 ”, W 99 ° 00 ’ 47 ”, 2000 m, bosque de pino-encino, NTP- 80, 1 a 30 - VIII- 1995, J. Márquez col. ” (m 22, MAAS). Same data, except: “ 1 a 30 - XI- 1996 ” (m 2, MAAS). Same data, except: “ 1 a 30 - IX- 1995 ” (m 16, MAAS). Same data, except: “ 1 a 30 - X- 1995 ” (m 5, MAAS). Same data, except: “ 1 a 30 - XII- 1995 ” (m 1, MAAS). Same data, except: “ 1 - V- 1995 ” (m 1, MAAS). Same data, except: “ 1 - 30 - VII- 1995 ” (m 1, MAAS). Same data, except: “ 1 a 30 - IX- 1995 ” (m 6, MAAS). Oaxaca: “ Santiago Yosondua, camino a Sta. Ma. Yolotepec, 2398 m, bosque de pino-encino, N 16 ° 51 ’ 13 ”, W 97 ° 33 ’ 43.6 ”, en hongos, 10 - VII- 2005, J. Asiain y J. Márquez cols. ” (m 7, f 6, CC-UAEH). “ Santiago Yosondua, camino a la Cañada de Garnica, 2299 m, bosque de pino-encino, N 16 ° 52 ’ 26.9 ”, W 97 ° 37 ’ 44.4 ”, en excremento caballar, 12 - VII- 2005, J. Asiain, S. Bautista, R. Bautista y J. Márquez cols. ” (m 1, CC-UAEH). “ La Cascada, camino El Vergel, bosque encino, 1917 m, N 16 ° 50 ’ 46.6 ”, W 97 ° 34 ’ 47.5 ”, NTP- 80 calamar, 12 - VII- 2005, J. Asiain, S. y R. Bautista, J. Márquez cols. ” (f 1, CC-UAEH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977367F1981AFA7E6FEC3FCB9.taxon	description	Figs. 2 d, 11 a, 17 f, 18 c, 21 c, 26 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977367F1981AFA7E6FEC3FCB9.taxon	description	Head: transverse; ratio length / width 0.83. Dorsal surface shiny; sulcate longitudinal midline visible only in anterior half of head. Eyes somewhat protruding, occupying almost 0.5 times the cephalic lateral length, in dorsal view widely separated. First antennomere as long as 2 – 3 combined, antennomeres 2 – 3 almost equal in length, 4 – 5 as long as wide, 6 – 10 transverse. Ratio mandibular length / cephalic length 0.93; right mandible with one middle dorsal tooth and one acute ventral tooth closer to dorsal tooth; left mandible only with one bilobed middle dorsal tooth; mandibular channel well developed, with carinate external and internal margins. Apical palpomere of maxillary and labial palpi almost twice the length of preapical palpomere. Ventral surface with seven to eight punctures at each middle part distributed toward sides. Ratio cephalic width / pronotal width 1.28. Neck with wrinkled microsculpture ventrally. Thorax: pronotum with five punctures in each dorsal row; slightly longer than wide (ratio 1.14) and wider at anterior corner than at posterior corner (ratio 1.21). Elytra and scutellum with fine setae moderately dense. Prosternum with a tranverse elevated zone behind anterior margin. Intercoxal process of mesoventrite shield-shaped, with a fine mid longitudinal carina initiating at anterior margin and extending until middle part of area between intercoxal process and transverse discal ridge latter V-shaped, not meeting margin of intercoxal process laterally (Fig. 11 a). External row of profemur with few and small spines (seven to eight), which are separated from apex; internal margin with three to four apical spines. Posterior legs with trochanter modified like hook, as long as, or slightly longer than 1 / 3 of the length of posterior femur, hook elongate and curved only at apex; posterior femur curved at level of overlap with hook, right femur with three spines and left femur with four spines of moderate size, placed at ventral internal margin, at hook level, forward of basal half; posterior tibia curved in apical third. Tarsomeres slender, slightly flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina slightly developed; adjacent depressed area well developed, with wide-superficial punctures that disappear towards posterior half of each tergite, where there are fine punctures. First visible tergite with a small median longitudinal ridge that extends from anterior margin to half its length; visible tergites 2 – 3 with a similar ridge, but shorter and less developed than ridge on first tergite; remaining tergites only with fine setae. Sternites with moderately dense fine setae; first three visible sternites with some wide-superficial punctures in their basal half. Male pregenital sternite with deep V-shaped emargination at posterior margin (Fig. 17 f). Genital sternite very long (3.5 times as long as wide), slightly symmetrical, with anterior margin almost flattened, anterior portion occupying 8 % and posterior portion 92 % of its length, apical emargination deep (Fig. 18 c). Abdominal styli slender at apex. Aedeagus: length 0.94 mm; elongate-pointed shape; apical 2 / 3 very slender in comparison with basal third, which is slightly wider and rounded; internal sac not visible (Fig. 21 c). Variability. In the two male paralectotypes, the measurements and ratios are: total length 9.0 and 10.1 mm, ratio length / width of head 0.86 and 0.91, ratio mandibular length / cephalic length 1.03 (in some specimens the mandibles could not be opened); ratio cephalic width / pronotal width 1.27 and 1.29; ratio length / width of pronotum 1.18 and 1.19; ratio anterior width / posterior width of pronotum 1.12 and 1.18. Each half of cephalic ventral surface with 6 – 7 setiferous punctures. Elytra and scutellum paler than in lectotype, almost the same tone than in the remaining body. Profemora with external row of spines more developed, row continuous almost from the base until 3 / 4 of their length. Femora of posterior legs with 1 – 5 spines at their internal margin. Ridge of tergites 2 – 3 from slightly developed to unconspicuous, but clearly visible in the first tergite. Taxonomic comments. No species in the trochanterinus group has a color similar to that of B. cariniventris, nor do they have several punctures on the ventral surface of the head, nor the carina in the middle apical part of the mesoventrite, nor the small median ridges of the first three visible abdominal tergites. From the rest of the species groups, it is easily distinguished by having the posterior trochanter of the males modified like a hook. The presence of this last character is what supports its placement in this group of species, but its almost all black or reddish-brown body color, the teeth of the right mandible (one half-ventral and the other half-dorsal) and its relatively small size, are characteristics that make it similar to some species of the viridipennis group and cast doubt on its correct assignment to this group of species. It should be tested in the future with a more comprehensive analysis. Another aspect to attract attention to is related to the absence of specimens other than the type series in the different collections studied despite the fact collecting has been carried out in Xalapa and its surroundings. It was decided to designate a lectotype of this species taking into account Article 74.7 of the International Code of Zoological Nomenclature (ICZN 1999) and its recommendations, in order to establish, in the best possible way, the identity of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977367F1981AFA7E6FEC3FCB9.taxon	materials_examined	Type material examined (three specimens): Lectotype (male, FMNH): “ Jalapa, Mexico, F. Schneider / 39 / cariniventris Bernhauer, Typus / Chicago NHMus M. Bernhauer Collection / Lectotype Belonuchus cariniventris Bernhauer, 1918, Márquez & Asiain des. 2022 ”. Paralectotypes: “ Jalappa, Mexiko, Dallerl / cariniventris Bernh. Cotypus / Chicago NHMus M. Bernhauer Collection ” (1 male, FMNH). Same data as lectotype, except “ Cotypus ” (1 male, FMNH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977357F1E81AFA592FEF0FDD9.taxon	description	Figs. 2 e, 13 k, 17 h, 18 d, 21 d, 28 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977357F1E81AFA592FEF0FDD9.taxon	description	Head: transverse in both sexes, with convex posterior corners; wider than long in males (ratio 0.66, range 0.59 – 0.74) and in females (ratio 0.82, range 0.79 – 0.87). Dorsal surface with punctures sparser than in majority of species, with similar distribution pattern; sulcate longitudinal midline visible at anterior 2 / 3 of head; front foveate. Eyes slightly longer than 0.5 times the cephalic lateral length, slightly protruding. Antennomere 4 slighly elongate, 5 as long as wide, 6 – 10 transverse. Mandibular length in males 1.52 times longer than head (range 1.11 – 1.79), females with mandibles almost as long as head (ratio 0.98, range 0.93 – 1.04); mandibles with microsculpture as waved lines at base; with two well separated teeth (basal and middle), with middle tooth placed slightly before half of mandibular length, teeth of medium to small size; mandibular channel with external margin widely separated from internal margin at base, internal margin carinate from base of mandible to beyond level of middle tooth. Apical palpomere of maxillary and labial palpi almost 1.25 times longer than preapical palpomere. Ventral surface smooth, with fine microsculpture as in dorsal surface. Head wider than pronotum in males (ratio 1.31, range 1.23 – 1.38) and slightly wider than pronotum in females (ratio 1.10, range 1.05 – 1.17). Thorax: pronotum with microsculpture and gloss as on head; each dorsal row formed by five punctures; pronotum slightly longer than wide in both sexes (ratio in males 1.09, range 0.97 – 1.33, in females 1.15, range 1.10 – 1.19); and slightly wider at anterior corners than at posterior corners (ratio in males 1.09, range 1.03 – 1.16, in females 1.04, range 1.00 – 1.07). Scutellum with denser punctures than on elytra, where they are moderately dense. Prosternum weakly elevated near anterior margin, which is slightly impressed. Intercoxal process of mesoventrite shieldshaped; transverse discal ridge little to moderately visible, broadly U-shaped. Profemur of males without defined internal margin, except near apex where there are four to five aligned spines of medium size; external margin with row of spines covering nearly 2 / 3 of its length, not reaching apex, spines increasing in size from base to apex, some of them as long as spines on anterior tibia; profemur of females also without defined internal margin, and spines of external margin shorter and less numerous than in males. Male metatrochanter modified like a hook that is situated somewhat ventrally, as long as 0.33 to 0.5 times the length of metafemur; metafemur notably curved at level of its overlap with hook; metatibia clearly curved on internal side of anterior third. Tarsomeres flattened dorsally (Fig. 13 k). Abdomen: visible tergites 1 – 3 with posterior basal transverse carina and depressed adjacent area clearly formed, with wide-superficial punctures covering almost all surface of visible tergite one, together with sparse, fine punctures; visible tergites 2 – 4 with wide-superficial punctures covering anterior half or slightly less, tergites 5 – 6 only with fine punctures; all wide-punctures are moderately dense. Visible sternites 1 – 4 with type of punctures as on tergites, slightly denser than in tergites. Male pregenital sternite with posterior margin narrowly, distinctly emarginate and with peculiar shape (Fig. 17 h). Male genital sternite very elongate (3.0 times longer than wide), slightly asymmetrical, anterior portion occupying 48 % and posterior portion 52 % of its length, apical emargination narrow and deep (Fig. 18 d). Male abdominal styli moderately wide and flattened at apex, somewhat convex at sides, covered by many reddish-brown or dark setae, mainly at apex. Aedeagus: length 1.7 mm; cone-shaped; apex subacute; in ventral view, sides gradually narrowed toward apex; in lateral view, base notably widened in relation to apical half; internal sac visible (Fig. 21 d). Variability. Great variation was observed in the measurements and ratios that were already indicated in the description, as well as variation due to sex and size of the specimens. Taxonomic comments. Belonuchus colon is the only species of the trochanterinus group and of any Mexican Belonuchus with a mainly reddish body, except for the head, neck and the last two visible abdominal segments (except the anterior border of the fifth) that are black. The shape of the hooks of the posterior legs of the males, the abdominal styli, the pregenital and genital sternite, as well as the aedeagus, reinforce their separation from any other species. Despite not having studied the syntypes of B. colon, the information included in the original description (Sharp 1885) and the clear diagnostic characters of this species leave no doubt of their correct identification.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977357F1E81AFA592FEF0FDD9.taxon	materials_examined	Material examined (221 males, 204 females): Mexico: Chiapas: “ San Cristóbal de las Casas, Reserva Biológica Huitepec, Cadera NE, bosque de encino, 2238 m, N 16 ° 14 ’ 798 ”, W 92 ° 40 ’ 848 ”, en pera podrida, 21 - XI- 1999, J. Márquez col. ” (1, MAAS). “ San Cristóbal de las Casas, Carretera SCLC- Sta. Rosa 1 km N de El Puerto, bosque de encino, 1687 m, N 16 ° 26 ’ 899 ”, W 92 ° 24 ’ 186 ”, NTP- 80, 21 - XI al 3 - XIII- 1999, J. Márquez col. ” (3, MAAS). Hidalgo: “ Huehuetla, Rio Blanco, bosque tropical perenifolio, 588 m, UTM (WG- 384), 14594809 E 2257383 N, NTP- 80 (calamar), 1 a 30 - V- 2010, C. Berriozábal col. ” (2, CC-UAEH). “ Juárez, bosque mesófilo perturbado, 1973 m, N 20 ° 45 ’ 59.7 ”, W 98 ° 49 ’ 1.8 ”, trampa de intercepción de vuelo # 1, 7 a 14 - III- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (4, CC-UAEH). “ La Misión, Palo Hueco 1.5 km al NE de Puerto de Naranjos, bosque mesófilo de montaña, 1197 m, N 21 ° 08 ’ 21 ”, W 99 ° 05 ’ 4.6 ”, en coprotrampa, del 10 al 24 - III- 2011, J. Márquez col. ” (1, CC-UAEH). “ Molango, Acuatitlán, bosque mesófilo de montaña, 1715 m, N 20 ° 45 ’ 38.4 ”, W 88 ° 42.6 ’ 50.7 ”, NTP- 80 (calamar) # 1, 15 a 29 - IV- 2011, J. Márquez col. ” (13, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 5 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 8 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 4 ” (7, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 7 ” (9, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3, 30 - IX a 21 - X- 2011 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 9, 30 - IX a 21 - X- 2011. J. Márquez col. ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 7 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (10, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 5 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 4 ” (2, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (1, CC- UAEH). “ Tenango de Doria, El Potrero, N 20 ° 18 ’ 40.2 ”, W 98 ° 13 ’ 51.8 ”, bosque mesófilo, 2182 m, NTP- 80 # 3, 18 a 25 - V- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Tenango de Doria, camino a La Viejita, bosque mesófilo de montaña, 1647 m, N 20 ° 19.0 ’ 37.9 ”, W 98 ° 14.0 ’ 39.7 ”, NTP- 80 (calamar) # 4, 1 a 15 - IX- 2011, J Márquez col. ” (3, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2 ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 7 ” (3, CC- UAEH). Same data, except: “ NTP- 80 (calamar) # 1 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 5 ” (3, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (4, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3, 29 - III a 12 - IV- 2011 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 7, 31 - III a 14 - IV- 2011 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2, 5 a 10 - V- 2013, N. Gutiérrez col. ” (4, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1, 11 a 16 - VI- 2013 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar), 12 - VIII - 2010, C. Cornejo col. ” (30, CC-UAEH). “ Tepehuacán de Guerrero, Chilijapa, bosque mesófilo de montaña, 1401 m, N 21 ° 12 ’ 5.1 ”, W 98 ° 51.8 ’ 2.1 ”, NTP- 80 (calamar) # 4, 11 a 25 - III- 2011. J. Márquez col. ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 8 ” (3, CC- UAEH). “ Tlanchinol, La Cabaña, bosque mesófilo de montaña, 1462 m, N 21 ° 01.333 ’, W 98 ° 38.650 ’, trampa de intercepción de vuelo # 2, 16 al 23 - VII- 2005, M. C. Pedraza, E. Pedraza y C. Ortiz cols. ” (1, CC-UAEH). “ 3 km N de Tlanchinol, 1450 m, bosque mesófilo de montaña, N 21 ° 1.328 ’, W 98 ° 38.77 ’, NTP- 80 (calamar), 16 - IV a 1 - V- 2003, J. Asiain y J. Márquez cols. ” (14, CC-UAEH). Same data, except: “ 16 - IV- 2003 ” (2, CC-UAEH). “ Tlanchinol, bosque mesófilo de montaña, NTP- 80 (calamar), 29 - IV a 29 - V- 1995, A. Soria col. ” (2, MAAS). “ Tlanchinol, bosque mesófilo de montaña, en necrotrampa temporal, 15 al 19 - V- 1996, J. Márquez col. ” (1, CC-UAEH). “ Tlanchinol camino a Apantlazol, El Pozo, bosque mesófilo de montaña, 1391 m, N 20 ° 59 ’ 6.73 ”, W 98 ° 37 ’ 39.86 ”, NTP- 80 (calamar) # 4, 16 a 30 - IV- 2011, J. Márquez col. ” (3, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 1 ” (5, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 5 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (2, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3, 1 a 22 - X- 2011 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 4, 1 a 22 - X- 2011 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 8, 1 a 22 - X- 2011 ” (3, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3, 16 a 30 - IV- 2011 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1 ” (5, CC-UAEH). “ Zacualtipán, camino a Sto. Domingo, bosque mesófilo de montaña, 1830 m, N 20 ° 37.749 ’, W 98 ° 34.851 ’, NTP- 80 (calamar), 30 - VII al 30 - X- 2003, J. Márquez y J. Asiain cols. ” (2, CC-UAEH). “ Zacualtipán, camino a Tizapán, bosque mesófilo de montaña, 1790 m, N 20 ° 38 ’ 44.5 ”, W 98 ° 36 ’ 7.2 ”, NTP- 80 (calamar) # 9, 20 - IX a 4 - X- 2011, J. Márquez col. ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 5 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 10 ” (10, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (7, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 1 ” (6, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2 ” (7, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 4 ” (10, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 1, 14 a 28 - IV- 2011 ” (2, CC- UAEH). Same data, except: “ NTP- 80 (calamar) # 7 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 9 ” (10, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 10 ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 8 ” (6, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 5 ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2, 14 a 28 - IV- 2011 ” (11, CC-UAEH). “ Zacualtipán camino a Tizapán, bosque mesófilo de montaña, 1790 m, N 20 ° 38 ’ 44.5 ”, W 98 ° 36 ’ 7.2 ”, trampa de intercepción de vuelo # 1, 14 a 28 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ 20 - IX a 4 - X- 2011 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2, 20 - IX a 4 - X- 2011 ” (3, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3, 20 - IX a 4 - X- 2011 ” (7, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Minas Viejas, bosque de encino, 1892 m, N 20 ° 55 ’ 5.2 ”, W 99 ° 12 ’ 41.1 ”, NTP- 80 (calamar), del 13 - VII al 18 - VIII- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (36, CC- UAEH). Same data, except: “ 11 - X al 17 - XI- 2007 ” (5, CC-UAEH). Same data, except: “ coprotrampa ” (1, CC- UAEH). Same data, except: “ 18 - VIII al 20 - IX- 2007, coprotrampa ” (2, CC-UAEH). Same data, except: “ necrotrampa ” (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, La Encarnación, bosque de encino, 2412 m, N 20 ° 52 ’ 1 ”, W 99 ° 12 ’ 50.3 ”, en excremento, 23 - VI- 2007, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Trancas, bosque de pino-encino, 2444 m, N 20 ° 48 ’ 12.222 ”, W 99 ° 14 ’ 41 ”, coprotrampa, 17 - VIII al- 19 - IX- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (1, CC-UAEH). Same data, except: “ 29 - V al 22 - VI- 2007 ” (1, CC- UAEH). Same data, except: “ 22 - VI al 12 - VII- 2007 ” (2, CC-UAEH). Same data, except: “ 19 - IX al 13 - X- 2007 ” (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, 2 km E de Durango, 1970 m, bosque de pino, N 20 ° 53 ’ 55.3 ”, W 99 ° 12 ’ 45.5 ”, NTP- 80 (calamar), 30 - VI- 2003, J. Asiain, J. Canales y J. Márquez cols. ” (1, CC-UAEH). “ Zimapán, El Salto a 2 km al E de Durango, 14 Q 0477652, UTM 231197, bosque de encino, 2155 m, NTP- 80 # 3, 28 - III a 04 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Zacualtipán, La Mojonera, N 20 º 37 ’ 59 ”, W 98 º 35 ’ 48 ”, 1886 m, bosque mesófilo de montaña perturbado, NTP- 80 (calamar), 28 - II a 29 - IV- 2004, J. Asiain y J. Márquez cols. ” (5, CC-UAEH). Same data, except: “ mayo-junio, 2004 ” (1, CC-UAEH). “ Zacualtipán, camino a Santo Domingo, N 20 º 37 ’ 44.9 ”, W 98 º 34 ’ 51.06 ”, 1830 m, bosque mesófilo de montaña, NTP- 80, 28 - II a 29 - IV- 2004, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). Puebla: “ Zacapoaxtla, Ex-hacienda Apulco, cascada La Gloria, N 19 ° 54´12 ”, W 97 ° 37´00 ”, 1,508 m, dentro de cañada bosque mesófilo de montaña rodeado por pinos, trampa de intercepción de vuelo, 18 a 28 - V- 2021, familia Márquez-Asiain cols. ” (21, MAAS). Same data except: “ NTP- 80 (calamar) ” (1, MAAS). Veracruz: “ Córdoba, camino a Plan de Ayala, bosque mesófilo de montaña, 1352 m, N 18 ° 57 ’ 15.2 ”, W 96 ° 58 ’ 41 ”, NTP- 80 (calamar), V a VI- 1999, J. Asiain, Q. Santiago, J. Márquez. ” (6, MAAS). “ Cosmatepec, Tecoac, bosque mesófilo de montaña, 1750 m, 26 - VII al 23 - IX- 1995, NTP- 80 (calamar) # 909, M. A. Pensado y Q. Santiago cols. ” (2, MAAS). Same data, except: “ 11 - III a 8 - IV- 1995 ” (1, QJSJ). “ Huayacocotla, Helechales, San Antonio, bosque mesófilo de montaña, 1434 m, N 20 ° 40 ’ 23.4 ”, W 98 ° 23 ’ 39.6 ”, NTP- 80 (calamar) # 4, 06 - III a 2 - IV- 2006, F. Ramírez col. ” (5, CC-UAEH). “ Huayacocotla, Helechales, bosque mesófilo de montaña, 1936 m, N 20 ° 37.5 ’ 25.0 ”, W 98 ° 27.6 ’ 49 ”, NTP- 80 (calamar) # 7, 19 - III a 2 - IV- 2011, J. Márquez col. ” (9, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (15, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 1 ” (20, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (1, CC-UAEH). “ Xalapa, Macuiltepetl, Arca Verde, N 19 ° 32´53.46 ”, W 96 ° 55´9.58 ”, 1552 m, coprotrampa, 2 - VII- 2013, V. Cruz, F. Sandoval y E. Montes de Oca cols. ” (3, QJSJ). Same data, except: “ N 19 ° 32´54.12 ”, W 96 ° 55´10.8 ”, 1546 m, NTP- 80 ” (2, QJSJ). Same data, except: “ 23 - VII- 2013 ” (1, QJSJ). Same data, except: “ N 19 ° 32´49.2 ”, W 96 ° 55´12.12 ”, 1538 m ” (1, QJSJ).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977327F1D81AFA4B2FD2DFC65.taxon	description	Figs. 2 f, 14 d, 17 i, 18 e, 21 e, 26 b Total body length 11.6 mm. Black on head, pronotum, sixth visible abdominal segment, major part of fifth visible segment (except anterior border), and abdominal styli. Reddish on elytra, legs, sterna, anterior border of fifth visible abdominal segment and visible segments 1 – 4. Reddish-brown on two apical antennomeres, mandibles, maxillary and labial palpi, scutellum and genital sternite. Head: transverse, ratio length / width 0.74. Dorsal surface with sulcate longitudinal midline clearly visible in more than anterior half of cephalic length; front moderately foveate at space between antennal insertions. Eyes nearly 0.5 times the cephalic lateral length, slightly protruding laterally. Antennomeres 4 – 5 elongate, 6 – 8 almost as long as wide, 9 – 10 slightly transverse. Mandibles 1.2 times longer than head; each with two well separated teeth (basal and middle), apical area somewhat curved, mandibular channel well developed, external margin well separated from internal margin at base, internal margin extending forward as impressed line beyond level of middle tooth. Maxillary palpi with apical palpomere near 1.25 times longer than preapical palpomere. Labial palpi with apical palpomere 1.1 times longer than preapical palpomere. Head 1.3 times wider than pronotum. Neck with moderate wrinkled microsculpture on ventral surface. Thorax: left dorsal row of pronotum with five punctures and right dorsal row with six punctures; slightly longer than wide (ratio 1.13) and almost as wide at anterior corners as at posterior corners (ratio 1.03). Scutellum with similar punctures as on elytra, slightly denser. Elytra with fine, moderately dense punctures. Prosternum slightly elevated close to anterior margin. Intercoxal process of mesoventrite acute and V-shaped; transverse discal ridge very fine, slightly acute, interrupted at middle part. Profemur with external row of spines initiating distant from base and ending distant from apex, spines moderately dense, longer spines placed at anterior part, as long as apical spines of internal margin. Metatrochanter modified like a hook, as long as 0.4 times the length of metafemur; metafemur slightly flattened and curved at level of overlap with hook, reaching up to half its length; metatibia weakly curved a little in front of its apical half. Abdomen: first visible tergite with posterior basal transverse carina clearly visible, moderately visible on tergite 2 and slightly visible on tergite 3; depressed adjacent area with denser punctures than on remaining part of each segment, where punctures are fine and moderately dense. Male pregenital sternite not emarginate at posterior margin, with a tiny medioapical projection (Fig. 17 i). Male genital sternite moderately elongate (2.67 times as long as wide), slightly asymmetrical, anterior portion occupying 48 % and posterior portion 52 % of its length, apical emargination moderately deep but very narrow (Fig. 18 e). Abdominal styli black, moderately wide and flattened at apex (Fig. 14 d), with large, dense setae, apex of styli as wide as apical width of metatibiae. Aedeagus: length 1.6 mm; elongate-convex shape; apex subacute, somewhat rounded; in ventral view, basal half of oval shape and slightly wider than apical half, in lateral view, basal half notably wider than apical half; internal sac visible (Fig. 21 e). Variability. An additional male and female were studied. Male with total body length 12.6 mm, ratio length / width of head 0.65; ratio mandibular length / cephalic length 1.7; ratio length / width of pronotum 1.09; ratio anterior width / posterior width of pronotum 1.1; apical palpomere almost as long as preapical palpomere in maxillary and labial palpi; antennomeres 1 – 3 black, apical antennomere reddish-brown; head shape transverse, with very long mandibles; elytra with dark punctures; scutellum reddish; pregenital sternite with medial projection of posterior margin indistinguishable. Female with total body length 11.5 mm; ratio length / width of head 0.8; ratio mandibular length / cephalic length 1.0; ratio length / width of pronotum 1.2; ratio anterior width / posterior width of pronotum 1.0; antennomeres 1 – 3 reddish, remaining antennomeres black; each dorsal row of pronotum with six punctures; scutellum reddish-brown; reddish anterior portion of visible tergite five wider than in male, near 1 / 4 of their total width. Taxonomic comment. This species is very similar to B. trochanterinus from Guatemala, but in B. confusus the abdominal styli of males are slightly less widened at apex and more oval-shaped, the pregenital sternite is not emarginate at posterior margin, but with a small medioapical projection, and the genital sternite and aedeagus are different. In B. trochanterinus the abdominal styli of males are widened and not as straight toward apex, male pregenital sternite slightly emarginate at posterior margin, and genital sternite and aedeagus are different. Belonuchus alternans and B. magnistylus also have the abdominal styli of males little to notably widened at apex, but are easily separated from B. confusus because they have more than the last two abdominal segments black, while in B. confusus only the last two abdominal segments are black. There are other species with a coloration pattern similar to B. confusus, such as B. tenuistylus and B. metafemoralis, but they lack the widened male abdominal styli.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977327F1D81AFA4B2FD2DFC65.taxon	etymology	Etymology. The name of this species refers to the fact that it can be confused with B. alternans and with B. trochanterinus.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977327F1D81AFA4B2FD2DFC65.taxon	materials_examined	Type material (two males, one female): Holotype (male, FMNH): “ Mexico: Chiapas, 8 mi N Pueblo Nuevo Solistahuacán, 6000 ’, VIII- 26, 27 - 1973 / white polypore fungus, A. Newton / J. F. Lawrence Lot. No. 3523 ”. Paratypes: same data as holotype (m 1, f 1, FMNH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977317F1C81AFA5EEFBC8F9ED.taxon	description	Figs. 2 g, 10 a, 12 j, 17 j, 18 f, 21 f, 26 b Total body length 11.3 mm. Black on almost entire body, except for reddish elytra, tibiae, tarsomeres and mesoventrite. Apical antennomere paler than previous ones, anterior half of mesoventrite black and posterior half reddish, genital segment brown. Head: transverse, ratio length / width 0.66, sides behind eyes and posterior corners somewhat rounded. Dorsal surface with punctures less dense than in majority of species; sulcate longitudinal midline visible for almost entire cephalic length, except in posterior fourth; front slightly foveate. Eyes slightly longer than 0.5 times the cephalic lateral length, not protruding at sides. Antennomeres 4 – 7 elongate, 8 – 10 as long as wide. Mandibles 1.43 times longer than head; with two well separated teeth (basal and middle) of moderate size; external channel slightly developed, external and internal margins well separated at base, internal margin carinate at base, extending upwards like impressed line, which exceeds the level of middle tooth. Apical palpomeres of maxillary palpi almost as long as, or slightly longer than preapical palpomere. Apical palpomere of labial palpi nearly 1.25 times as long as preapical palpomere. Head 1.25 times wider than pronotum. Thorax: each dorsal row of pronotum with five punctures; pronotum almost as long as wide (ratio 1.06), but wider at anterior corners than at posterior corners (ratio 1.14). Scutellum with denser punctures than on elytra, but concentrated at center, with their sides smooth; elytra with fine, sparse punctures. Prosternum slightly elevated before anterior margin. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge weakly developed, also acute posteriorly. Profemur without defined internal margin, only near its apex where there are few short spines combined with setae, external margin with spines that initiate slightly before midpoint and not reaching the apex, increasing in size towards apex, but are not very long. Metatrochanter modified like slender and long hook, distinctly curved and acute at apex, as long as half length of metafemur (Fig. 12 j); metafemur curved at level of overlap with hook; metatibia internally curved in its anterior third. Tarsomeres flattened dorsally. Abdomen: glossy and iridiscent; first three visible tergites with posterior basal transverse carina well developed, adjacent area clearly depressed, but narrow and with fine punctures, remaining abdomen covered with sparse, fine punctures. Pregenital sternite slightly emarginate at posterior margin, with sides of emargination of peculiar shape (Fig. 17 j). Male genital sternite moderately elongate (2.61 times longer than wide), slightly asymmetrical, anterior portion occupyig 49 % and posterior portion 51 % of its length, apical emargination deep (Fig. 18 f). Abdominal styli black and very slender. Aedeagus: length 1.85 mm; shape oval-elongate; apex slender and acute, occupying almost 1 / 2 of anterior half, becoming gradually wider toward base; basal half oval-rounded, notably wider than apical half; internal sac visible, with some microsetae before apex (Fig. 21 f). Variability. Total body length in males 10.5 mm (range 9.5 – 11.3 mm), in females 10.6 (range 8.5 – 11.6); ratio length / width of head in males 0.75 (range 0.61 – 0.81), in females 0.83 (range 0.78 – 0.84); ratio mandibular length / cephalic length in males 1.18 (range 0.96 – 1.37), in females 1.02 (range 0.96 – 1.08); ratio cephalic width / pronotal width in males 1.21 (range 1.14 – 1.37), in females 1.10 (range 1.07 – 1.15); ratio length / width of pronotum in males 1.12 (range 1.07 – 1.19), in females 1.17 (range 1.14 – 1.21); ratio anterior width / posterior width of pronotum in males and females 1.02 (range 1.00 – 1.04). Variation was also noted in the color of last and penultimate antennomere that may be lighter than the previous ones or almost the same; anterior half of mesoventrite black, posterior half reddish, brown or almost black. Taxonomic comments. This species can be confused only with B. pulcher because both have a glossy black body, with elytra and part of legs reddish. In B. julietitae, the tibiae and tarsomeres are reddish, the metaventrite is also reddish, the genital sternite is less wide and more acute at its base, and the aedeagus is smaller, as well as its apex; whereas B. pulcher has only the coxae black and the remaining segments of the legs are reddish, the metaventrite is dark or almost black, the male genital sternite is wider and less acute at its base, and the aedeagus is larger, with its apex also larger.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977317F1C81AFA5EEFBC8F9ED.taxon	etymology	Etymology. The name of this species is dedicated with great affection to Julieta Márquez Asiain (daughter of the authors).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977317F1C81AFA5EEFBC8F9ED.taxon	materials_examined	Type material (79 males, 47 females): Holotype (male, CC-UAEH) “ México: Hidalgo, Zacualtipán, La Mojonera, N 20 º 37 ’ 59 ”, W 98 º 35 ’ 48 ”, 1886 m, bosque mesófilo de montaña perturbado, NTP- 80 (calamar), 28 - II a 29 - IV- 2004, J. Asiain y J. Márquez cols. “. Paratypes: Mexico: Hidalgo: “ Acaxochitlán, Tlazintla, bosque encino-pino, 2149 m, N 20 ° 09 ’ 7.96 ”, W 98 ° 11 ’ 1.83 ”, NTP- 80 (calamar), (without date) J. Islas col. ” (1, CC-UAEH). “ Tenango de Doria, camino a La Viejita, bosque mesófilo de montaña, 1647 m, N 20 ° 19 ’ 37.9 ”, W 98 ° 14 ’ 39.7 ”, trampa de intercepción de vuelo # 1, 1 al 15 - IX- 2011, J. Márquez col. ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 6 ” (1, CC-UAEH). “ Tenango de Doria, El Potrero, N 20 ° 18 ’ 40.2 ”, W 98 ° 13 ’ 51.8 ”, bosque mesófilo, 2182 m, NTP- 80 (calamar) # 3, 18 a 25 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Zacualtipán, La Mojonera, N 20 º 37 ’ 59 ”, W 98 º 35 ’ 48 ”, 1886 m, bosque mesófilo de montaña perturbado, NTP- 80 (calamar), mayo-junio- 2004, J. Asiain y J. Márquez cols. ” (14, CC-UAEH). Same data, except: “ 28 - II a 29 - IV- 2004 ” (93, CC-UAEH). “ Zacualtipán, camino a Santo Domingo, bosque mesófilo de montaña, 1830 m, N 20 ° 37.749 ’, W 98 ° 34.85 ’, NTP- 80 (calamar), 29 - XII- 2003 al 28 - II- 2004, J. Asiain y J. Márquez cols. ” (4, CC-UAEH). “ Zacualtipán, camino a Santo Domingo, bosque mixto o mesófilo perturbado, N 20 ° 38 ’ 00.7 ”, W 98 ° 34 ’ 00.5 ”, trampa cebada con hongos, 21 al 28 - IX- 2003, J. Asiain y J. Márquez cols. ” (1, CC-UAEH). Same data, except “ trampa de intercepción de vuelo ” (2, CC-UAEH). “ Zacualtipán, bosque de pino, en tronco podrido, 22 y 23 - I- 1996, J. Márquez col. ” (1, MAAS). Veracruz: “ Coscomatepec, Tecoac, bosque mesófilo de montaña, 1750 msnm, NTP- 80 (calamar) # 758, 03 - VI a 1 - VII- 1995, M. A. Pensado y Q. Santiago cols. ” (1, MAAS; 1, QJSJ). Same data, except “ 6 - V a 3 - VI- 1995 ” (1, QJSJ).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977307F2281AFA066FDD7F871.taxon	description	Figs. 2 h, 12 k, 12 – l, 15 i, 18 h, 21 g, 29 a Total body length 11.2 mm. Black on head, pronotum, posterior 3 / 4 of fifth visible abdominal segment and entire sixth visible segment. Reddish on mouthparts (except mandibles), scutellum, elytra, legs, sterna, visible abdominal segments 1 – 4 and anterior 1 / 4 of fifth. Genital segment pale reddish. Head: transverse, ratio length / width 0.71. Dorsal surface with sulcate longitudinal midline slightly visible only at anterior half of head; front moderately foveate near anterior margin. Eyes nearly 0.5 times the cephalic lateral length, slightly protruding laterally. Antennomere 4 elongate, 5 – 10 transverse. Mandibles 1.37 times longer than head; with well separated basal and middle teeth; mandibular channel well developed, external margin clearly separated from internal margin at base, internal margin extending forward beyond level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Head 1.1 times wider than pronotum. Thorax: left dorsal row of pronotum with six punctures and right dorsal row with five punctures; pronotum slightly longer than wide and slightly wider at anterior corners than at posterior corners (both ratios 1.07). Scutellum reddish as elytra, with punctures denser than on elytra; elytra with fine punctures moderately dense. Prosternum reddish, without homogeneous color, zone behind anterior margin slightly elevated and with a fine transverse line. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge clearly visible, broadly U-shaped, slightly acute posteriorly, not meeting margin of intercoxal process laterally, although leading very close to it. Profemur with row of spines initiating slightly before half length and not reaching apex; internal apex with few spines; all spines of small to moderate size. Metatrochanter modified like a hook, reaching about 1 / 2 of the length of metafemur, hook almost straight in 3 / 4 of its length and only in apical fourth curved and acute (Fig. 12 – l); metafemur clearly curved at level of overlap with the hook; metatibia curved in anterior third. Tarsomeres dorsally flattened. Abdomen: first three visible tergites with posterior basal transverse carina well developed, adjacent area slightly depressed and covered with wide-superficial punctures that are moderately dense; remaining surface and following tergites with sparse, wide-superficial punctures combined with fine punctures; visible sternites 1 – 4 with wide-superficial punctures denser than on tergites 1 – 3, remaining sternites with sparse, wide-superficial punctures combined with fine punctures. Male pregenital sternite with weak, broadly arcuate emargination at posterior margin (Fig. 15 i). Male genital sternite moderately long (2.58 times longer than wide), very asymmetrical, anterior portion occupying 34 % and posterior portion 66 % of its length, apical emargination deep (Fig. 18 h). Abdominal styli slen- der. Aedeagus: length 1.5 mm; cone shaped with middle constriction; apex moderately acute; apical half slenderer than basal half, with sides gradually becoming narrower toward apex; basal half rounded; internal sac visible (Fig. 21 g). Variability. Total body length in males 10.3 mm (range 9.2 – 11.2 mm), in females 9.5 mm (range 8.3 – 10.5 mm); proportion length / width of head in males 0.78 (range 0.67 – 0.88) and in females 0.85 (range 0.83 – 0.88); males with mandibles moderately longer than head (ratio 1.16, range 0.91 – 1.50), females with mandibles shorter than head (ratio 0.84, range 0.73 – 0.88); head wider than pronotum in males (ratio 1.26, range 1.16 – 1.40), and in females (ratio 1.15, range 1.10 – 1.18); pronotum longer than wide in males (ratio 1.11, range 1.07 – 1.16), and in females (ratio 1.18, range 1.15 – 1.25), almost as wide at anterior corners as at posterior corners (ratio in males 1.05, range 1.02 – 1.07, in females 1.02, range 1.00 – 1.04); male metatrochanter modified like a hook that in large specimens is nearly 1 / 2 of the length of metafemur, but in small specimens is only an acute spine not reaching 1 / 5 of metafemur length. In addition to the above variation, in females the antennomeres 5 – 10 are more transverse and antennomere 4 is smaller than in males. There is great variation in the number of punctures forming each dorsal row of the pronotum (5: 5, 5: 6, 6: 5, 6: 6). The scutellum can be a little darker than the elytra or with the same tonality; a male specimen has the scutellum almost black. The fifth visible abdominal segment is commonly reddish in the anterior third and black in the posterior two thirds, but there is some variation in this ratio that does not become half reddish and half black. Taxonomic comments. This species was identified as B. zunilensis in the past (Navarrete-Heredia et al. 2002; Asiain et al. 2011, among others), since they are very similar and only the review of the type material allowed to recognize that they are two species. Both B. zunilensis and B. linuzensis are relatively easy to distinguish from the rest of the species in the trochanterinus group by having the scutellum of similar color as the elytra (reddish) and the last two visible abdominal segments almost completely black. They are distinguished because B. linuzensis has the metafemur curved at the level of its overlap with the hook and the metatibia is curved in the apical third, the male pregenital sternite is slightly emarginate at posterior margin, the male genital sternite is moderately elongate and very asymmetrical, and due to the shape of aedeagus; whereas B. zunilensis, despite having the male hook-like metatrochanter shorter than in B. linuzensis, the metafemur is curved in almost 1 / 2 of its length, the metatibia is straight, the male pregenital sternite is not emarginate at the posterior margin and has a peculiar shape (Fig. 17 n), the male genital sternite is very elongate and slightly asymmetrical, and the shape of the aedeagus is different.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977307F2281AFA066FDD7F871.taxon	etymology	Etymology. The name is an anagram of “ Zunil ”, in relation to the similarity it has with B. zunilensis.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977307F2281AFA066FDD7F871.taxon	materials_examined	Type material (91 males, 32 females): Holotype (male, CC-UAEH): “ México: Hidalgo, La Misión, Lomas del Pericón, bosque mesófilo de montaña, 1377 m, N 21 ° 60 ’ 46.0 ”, W 99 ° 6.0 ’ 15.6 ”, NTP- 80 (calamar), 29 - III al 05 - IV- 2009, J, Márquez, M. Rivera, M. Torres, M. Vargas y J. Sánchez cols. ”. Paratypes: Mexico: Hidalgo: “ Chapulhuacán, Puerto del Zopilote, bosque mesófilo de montaña, 1134 m, N 21 ° 09.9 ’ 7.9 ”, W 98 ° 55.8 ’ 04.0 ”, NTP- 80 (calamar), 28 - VIII a 11 - IX- 2011, J. Márquez col. ” (5, CC-UAEH). “ Chapulhuacán, Tamaulipas, bosque mesófilo de montaña, 1133 m, N 21 ° 09.9 ’ 7.9 ”, W 98 ° 55.8 ’ 04.0 ”, NTP- 80 (calamar) # 3, 12 a 26 - III- 2011. J. Márquez col. ” (1, CC-UAEH). “ Huehuetla, Rio Blanco, bosque tropical perennifolio, 588 m, UTM (WG- 384), 14594809 E, 2257303 N, NTP- 80 (calamar), 1 al 30 - V- 2010, C. Berriozábal col. ” (3, CC-UAEH). “ Jacala de Ledezma, 1 km E de El Durazno, bosque pino-encino- Junniperus, 1694 m, N 20 ° 3 ’ 11.1 ”, W 99 ° 1 ’ 20 ”, NTP- 80 (calamar), 8 al 16 - III- 2008, J. Márquez y J. Asiain cols. ” (7, CC-UAEH). “ Juárez, bosque mesófilo perturbado, 1973 m, N 20 ° 45 ’ 59.7 ”, W 98 ° 49 ’ 1.8 ”, NTP- 80 (calamar), 7 a 14 - III- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (3, CC-UAEH). “ La Misión, Lomas del Pericón, bosque mesófilo de montaña, 1377 m, N 21 ° 60 ’ 46.0 ”, W 99 ° 6.0 ’ 15.6 ”, NTP- 80 (calamar), 8 al 16 - III- 2008, J. Márquez y J. Asiain cols. ” (4, MAAS). Same data, except: “ 14 a 29 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ 26 - VIII a 9 - IX- 2011 ” (5, CC-UAEH). “ La Misión, Los Naranjos, Palo Hueco, bosque mesófilo de montaña, 1276 m, N 21 ° 08 ’ 06 ”, W 99 ° 05 ’ 02 ”, NTP- 80 (calamar) # 6, 10 a 24 - III- 2011, J, Márquez col. ” (2, CC-UAEH). “ La Misión, Lagunita de Pilas, El Divisadero, N 21 ° 08´15 ”, W 99 ° 07´08 ”, 1,210 m, mezcla encino-bosque tropical subcaducifolio, en NTP- 80 (cal.), 17 - IV a 11 - V- 2019, J. A. Lora Díaz col. ” (1 male, CC-UAEH). Same data except: “ coprotrampa, 11 - VI a 10 - VII- 2019 ” (1 male, CC-UAEH). Same data except: “ coprotrampa, 15 - IX a 12 - X- 2019 ” (2 males, CC-UAEH). “ Molango, Acuatitlán, bosque mesófilo de montaña, 1715 m, N 20 ° 45 ’ 38.4 ”, W 88 ° 42 ’ 50.7 ”, NTP- 80 (calamar) # 6, 15 a 29 - IV- 2011, J. Márquez col. ” (14, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo ” (1, CC-UAEH). Same data, except: “ hojarasca cernida, 12 - IV- 2011 ” (1, CC-UAEH). Same data, except: “ 30 - V- 2011 ” (1, CC-UAEH). “ Pacula, Puerto Grande, bosque de encino, 2103 m, N 20 ° 53.812 ’, W 99 ° 19.568 ’, NTP- 80 # 1, 28 - III al 24 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Tenango de Doria, camino a La Viejita, bosque mesófilo de montaña, 1647 m, N 20 ° 19 ’ 37.9 ”, W 98 ° 14 ’ 39.7 ”, NTP- 80 (calamar), 12 - VIII- 2010, C. Cornejo col. ” (13, CC-UAEH). “ Tepehuacán de Guerrero, San Juan Ahuehueco, selva mediana, 1016 m, N 21 ° 01.784 ’, W 98 ° 54.277 ’, NTP- 80 (calamar) # 2, 29 - III al 05 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Tepehuacán de Guerrero, Chilijapa, bosque mesófilo de montaña, 1401 m, N 21 ° 1.2 ’ 5.1 ”, W 98 ° 51.8 ’ 2.1 ”, NTP- 80 (calamar) # 2, 11 a 25 - III- 2011, J. Márquez col. ” (1, CC-UAEH). “ Tlanchinol camino a Apantlazol, El Pozo, bosque mesófilo de montaña, 1391 m, N 20 ° 59 ’ 6.73 ”, W 98 ° 37 ’ 39.86 ”, NTP- 80 (calamar), 16 a 30 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ 1 a 22 - X- 2011 ” (2, CC-UAEH). “ Zimapán, El Salto, a 2 km al E de Durango, bosque de encino, 2099 m, N 20 ° 54.023 ”, W 99 ° 12.933 ’, NTP- 80 # 1, 28 - III a 4 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (2, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Minas Viejas, bosque de encino, 1892 m, N 20 ° 55 ’ 5.2 ”, W 99 ° 12 ’ 41.1 ”, NTP- 80 (calamar), 13 - VII al 17 - VIII- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (3, CC-UAEH). Same data, except: “ 11 - X al 17 - XI- 2007 ” (7, CC-UAEH). Same data, except: “ coprotrampa, 11 - X a 17 - XI- 2007 ” (1, CC-UAEH). “ P. N. Los Mármoles, Zimapán, Trancas, bosque de pino-encino, 2444 m, N 20 ° 48 ’ 12.222 ”, W 99 ° 14 ’ 41 ”, coprotrampa, 22 - VI al 12 - VII- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (1, CC-UAEH). Puebla: “ Zacapoaxtla, Ex-hacienda Apulco, cascada La Gloria, N 19 ° 54´12 ”, W 97 ° 37´00 ”, 1,508 m, dentro de cañada bosque mesófilo de montaña rodeado por pinos, NTP- 80, 18 a 28 - V- 2021, familia Márquez-Asiain cols. ” (3, MAAS). Veracruz: “ Córdoba, camino a Plan de Ayala, bosque mesófilo de montaña, 1352 m, N 18 ° 57 ’ 15.2 ”, W 96 ° 58 ’ 41 ”, NTP- 80 (calamar), V a VI- 1999, J. Asiain, Q. Santiago, J. Márquez cols. ” (6, MAAS). “ Córdoba, San Rafael, Calería, Ojo de Agua, selva media subcaducifolia, 1127 m, N 18 ° 57 ’ 15 ”, W 96 ° 56 ’ 24 ”, NTP- 80 (calamar), 19 - II al 20 - III- 1999, Q. Santiago, J. Asiain y J. Márquez cols. ” (9, MAAS). Same data, except: “ 23 - IX a 23 - X- 1998 ” (2, MAAS). Same data, except: “ 2 - II a 2 - III- 1999 ” (3, MAAS). Same data, except: “ 20 - III a 17 - IV- 1999 ” (3, MAAS). Same data, except: “ naranja podrida, 20 - III- 1999 ” (2, MAAS). “ Jalapa, La Herradura, N 19 ° 31 ’ 07 ”, W 96 ° 53 ’ 45 ”, 1292 m, bosque mesófilo de montaña, NTP- 80 (calamar), 26 - Ix a 26 - X- 1998, Q. Santiago, J. Márquez y J. Asiain cols. ” (1, MAAS). “ Totutla Mata Oscura, 1 km S de Zacuapan, selva mediana subcaducifolia, 864 m, N 19 ° 12 ’ 23 ”, W 96 ° 50 ’ 32 ”, necrotrampa (calamar), 20 - II a 19 - III- 1999, J. Asiain, Q. Santiago y J. Márquez cols. ” (3, MAAS). “ Huatusco, Coxcontla, bosque mesófilo de montaña perturbado, 1250 m, NTP- 80 (calamar), 14 - I a 11 - II- 1995, M. A. Pensado y Q. Santiago cols. ” (4, QJSJ). Same data, except: “ 19 - XI a 17 - XII- 1994, coprotrampa ” (1, QJSJ). Same data, except: “ 3 - VI a 1 - VII- 1995, coprotrampa ” (1, QJSJ). Same data, except: “ 17 - XII- 1994 a 14 - I- 1995, NTP- 80 (calamar) ” (1, QJSJ). Same data, except: “ 8 - IV a 6 - V- 1995, NTP- 80 (calamar) ” (1, QJSJ).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770D7F2081AFA6ABFCB0FD15.taxon	description	Figs. 3 a, 14 f, 16 h, 18 g, 21 h, 26 a Total body length 11.2 mm. Black on head, antennae, pronotum, scutellum, visible abdominal segments 4 – 6 (except anterior borded of fourth) and abdominal styli. Reddish on elytra, legs, sterna (except the anterior half of prosternum), visible abdominal segments 1 – 3 and anterior border of fourth. Mandibles, maxillary and labial palpi, and genital segment brown. Head: transverse; ratio length / width 0.73. Dorsal surface with punctures slightly sparser than in the majority of species; sulcate longitudinal midline visible in anterior half of head; front moderately foveate between antennal insertions. Eyes slightly longer than 0.5 times the cephalic lateral length, slightly protruding at sides. Antennomeres 4 – 6 elongate, 7 as long as wide, 8 – 10 slightly transverse. Mandibles 1.37 times longer than head; with two moderately separated teeth (basal and middle) of similar size; mandibular channel moderately developed; external margin slightly separated from internal margin at base, internal margin carinate, extending slightly forward of level of middle tooth. Apical palpomere of maxillary and labial palpi almost 1.25 times longer than preapical palpomere. Ventral surface with microscuplture as on dorsal surface, but less conspicuous and with very fine, sparse punctures. Head 1.19 times wider than pronotum. Neck in ventral view with coarser microsculpture than on ventral surface of head. Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio 1.13) and almost as wide at anterior corners as at posterior corners (ratio 1.03). Scutellum with punctation denser than on elytra, latter with fine and sparse punctation. Prosternum slightly elevated behind anterior margin. Intercoxal process of mesoventrite shield-shaped; discal transverse ridge moderately visible, with similar shape as intercoxal process and not meeting it laterally. Profemur with external row of spines initiating near basal third and not reaching apex, not even reaching level of first apical spine of internal margin, not more than 10 short spines; with three or four internal spines near apex longer than external spines. Metatrochanter modified like elongate hook, curved and acute at apex, almost as long as half length of metafemur; metafemur curved at level of overlap with hook and slightly in front; metatibia with internal part weakly curved in anterior third. Tarsomeres dorsally flattened, but not very distinctly. Abdomen: first three visible abdominal tergites with posterior basal transverse carina well developed, adjacent area clearly depressed, less so on tergite 3; depression with dense wide-superficial punctures that decrease in density posteriad on each tergite; entire surface of each tergite additionally with moderately dense and fine punctures. All sternites with wide-superficial punctures denser than on tergites, but concentrated at anterior 1 / 4 to 1 / 2, on remaining surface of sternites these punctures are sparse and combined with fine punctures. Male pregenital sternite with U-shaped emargination at posterior margin (Fig. 16 h). Male genital sternite moderately elongate (2.6 times longer than wide), slightly asymmetrical, anterior portion occupying 40 % and posterior portion 60 % of its length, apical emargination deep (Fig. 18 g). Abdominal styli black and broad (as wide as, or slightly wider than apex of metafemur), with curved sides (more on external side) and apical zone flattened; ventrally with a series of 5 – 6 black and thickened setae placed before apex (Fig. 14 f). Aedeagus: length 1.9 mm; oval-elongate shape; apex subacute, quite broad; in ventral view, basal half wider than apical half, mainly in comparison with apical portion where the sides are gradually becoming narrower toward apex; in lateral view, basal half is notably wider than apical half, oval-rounded shape; internal sac visible (Fig. 21 h). Variability. Total body length in males 11.55 mm (range 11.5 – 11.6), in females 10.3 mm (without variation); ratio length / width of head in males 0.74 (range 0.72 – 0.76), in females 0.89 (without variation); ratio mandibular length / cephalic length in males 1.345 (range 1.33 – 1.36), in females 0.84 (without variation); ratio cephalic width / pronotal width in males 1.185 (range 1.18 – 1.19), in females 1.06 (range 1.04 – 1.08); ratio length / width of pronotum in males 1.125 (range 1.12 – 1.13), in females 1.19 (without variation); ratio anterior width / posterior width of pronotum in males 1.04 (range 1.03 – 1.05), in females 1.00 (without variation). In addition, there is a variation in the color of the last or the last two antennomeres, which may be brown or even lighter; on the prosternum a transverse line can be present or not that delimits the elevated area; a female specimen has the procoxae and mesocoxae, and the prosternum and mesoventrite brown (dark); in one female the fourth visible abdominal segment is black in basal half and reddish in apical half; in two males, the emargination at the posterior margin of the pregenital sternite was more pronounced. Taxonomic comments. Among the other three species with enlarged abdominal styli in males, B. magnistylus may be more easily confused with B. alternans, since they have the fourth visible abdominal segment mostly black; in the taxonomic comments of this last species their differences have been commented. The other two species with enlarged abdominal styli are B. confusus and B. trochanterinus, but they are distinguished from B. magnistylus because the fourth visible abdominal segment is all reddish.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770D7F2081AFA6ABFCB0FD15.taxon	etymology	Etymology. The name is a combination of “ magnus ” and “ stylus ” to highlight one of its diagnostic characteristics, the large styli.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770D7F2081AFA6ABFCB0FD15.taxon	materials_examined	Type material (six males, five females): Holotype (male, CC-UAEH): “ México: Chiapas, San Cristóbal de las Casas, Reserva Biológica Huitepec, ladera NE, bosque de encino, 2238 m, N 16 ° 14 ’ 798 ”, W 92 ° 40 ’ 848 ”, en pera podrida, 21 - XI- 1999, J. Márquez col. ” Paratypes: Same data as holotype (3, CC-UAEH; 2, MAAS). Mexico: Chiapas: “ cerca de San Juan Panana, (cerca de El Triunfo), cultivo de café y selva media perturbada, 1480 m, N 15 ° 23 ’ 920 ”, W 92 ° 30 ’ 412 ”, en hojarasca y rocas de riachuelo, 22 - XI- 1999, J. Márquez col. ” (1, MAAS). “ San Cristobal de las Casas, Carretera SCLC-Sta. Rosa, 1 km N El Puerto, bosque de encino, 1687 m, N 16 ° 26 ’ 899 ”, W 92 ° 24 ’ 186 ”, NTP- 80, 21 - XI al 3 - XII- 1999, J. Márquez col. ” (2, MAAS). “ San Cristobal (near), Sendero Nat. Oxyoquet, 2 - VII- 1991 / human dung pitfall trap, T. K. Phillips & P. Kovarik, Field Museum of Natural History ” (m 1, FMNH). “ San Cristobal (near), Sendero Nat. Oxyoquet, 2 - VII- 1991 / human dung pitfall trap, T. K. Phillips & P. Kovarik, Field Museum of Natural History ” (m 1, FMNH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770C7F2781AFA50BFD98FAE9.taxon	description	Figs. 3 b, 12 m, 15 j, 18 i, 21 i, 27 b Total body length 11.4 mm. Black on head, antennae, pronotum, posterior 3 / 4 of fifth visible abdominal segment and all sixth, prosternum, anterior half of mesoventrite and abdominal styli. Reddish on elytra, legs, posterior half of mesoventrite, metaventrite, first four visible abdominal segments and anterior 1 / 4 of fifth visible segment. Mandibles, maxillary and labial palpi, and genital segment brown. Head: transverse, slightly convex at posterior corners and on vertex; ratio length / width 0.74. Dorsal surface with indistinctly visible microsculpture of waved lines; sulcate longitudinal midline visible in anterior half of head; front with a narrow area clearly foveate near anterior margin. Eyes nearly 0.5 times the cephalic lateral length, not protruding at sides. Antennomere 4 slightly elongate, 5 almost as long as wide, 6 – 10 transverse. Mandibles 1.41 times longer than head; with two well separated teeth, basal tooth longer than middle tooth; mandibular channel with external margin widely separated from internal margin at base, internal margin carinate, extending forward slightly beyond level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Head 1.25 times wider than pronotum. Neck with wrinkled microsculpture ventrally. Thorax: each dorsal row of pronotum with four punctures; pronotum slightly longer than wide (ratio 1.13), almost as wide at anterior corners as at posterior corners (ratio 1.03). Scutellum and elytra with fine, sparse punctures and setae. Prosternum with area close to anterior margin slightly elevated, with microsculpture as on neck. Anterior half of mesoventrite with microsculpture as on neck; intercoxal process shield-shaped, lateral margin well developed; transverse discal ridge broadly U-shaped, laterally meeting with lateral margin of intercoxal process. Profemur with external row of spines initiating in basal fourth and reaching apex, but interrupted before apex, as if one or two spines were missing; spines increasing in size toward apex; internal margin developed only near apex, where bearing few spines. Metatrochanter modified like a hook, wide in basal 2 / 3 and slender and straight in distal third, ending in an angle of 90 °, hook as long as 1 / 3 of length of metafemur (Fig. 12 m); metafemur with a convex carina near base of its ventral surface, delimiting a slight to moderate cavity to accommodate the hook. Metatibia weakly curved at internal margin near apex. Tarsomeres slightly flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed, adjacent area slightly depressed, narrow and with sparse wide-superficial punctures; remaining surface of tergites 1 – 3 and remaining tergites with fine, sparse punctures and setae. Anterior half of visible sternites 1 – 4 with wide-superficial punctures denser than on tergites 1 – 3, remaining surface only with fine, sparse punctures and setae. Male pregenital sternite with slight, broadly arcuate emargination (Fig. 15 j). Male genital sternite short (2.0 times longer than wide), slightly asymmetrical, anterior portion occupying 30 % and posterior portion 70 % of its length, apical emargination deep (Fig. 18 i). Abdominal styli slender. Aedeagus: length 1.3 mm; elongate shape, with a constriction in apical third; apex slightly rounded in ventral view and slightly acute in lateral view; in lateral view, basal half wider than apical half; internal sac visible (Fig. 21 i). Variability. Measurements and ratios (males n = 3, females n = 3): total body length in males 10.9 mm (range 10.5 – 11.5 mm), in females 10.7 (range 10.3 – 11.3 mm); ratio length / width of head in males 0.78 (range 0.76 – 0.80), in females 0.91 (range 0.90 – 0.93); ratio mandibular length / cephalic length in males 1.23 (range 1.04 – 1.37), in females 0.89 (range 0.81 – 1.00); ratio cephalic width / pronotal width in males 1.15 (range 1.13 – 1.19), in females 1.04 (range 1.02 – 1.06); ratio length / width of pronotum in males 1.11 (range 1.10 – 1.13) in females 1.14 (range 1.10 – 1.18); ratio anterior width / posterior with of pronotum in males 1.01 (range 1.00 – 1.03), in females 1.0 (without variation). In addition, there is a variation in the sulcate longitudinal midline of the head that can go further back than the eye level; dorsal rows of punctures in the pronotum are predominantly 5: 5, but 6: 6 and 4: 5 also occur; in a female and a male the wide-superficial punctures of the abdomen appear denser; in one female the elytra and legs are reddish-dark, and the abdomen is shiny brown. Taxonomic comments. This species is very similar to B. tenuistylus, from which it differs in the fifth visible abdominal segment black in basal 3 / 4 and reddish in anterior 1 / 4, the metafemur of males has a cavity delimited by a carina where each hook is possibly accommodated, and in the particular shape of aedeagus and genital sternite; while B. tenuistylus has the basal half of the fifth visible abdominal segment black and the apical half reddish, the metafemur of males lacks the cavity and carina, and they have a different aedeagus and genital sternite.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770C7F2781AFA50BFD98FAE9.taxon	etymology	Etymology. The name of this species refers to the femur of the male posterior legs, with a cavity delimited by a carina, a structure that has not been observed in any other species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770C7F2781AFA50BFD98FAE9.taxon	materials_examined	Type material (seven males, five females): Holotype (male, CC-UAEH): “ México: Hidalgo, Zimapán, Parque Nacional Los Mármoles, Minas Viejas, bosque de encino, 1892 m, N 20 ° 55 ’ 5.2 ”, W 99 ° 12 ’ 41.1 ”, NTP- 80 (calamar), 11 - X al 17 - XI- 2007, J. Márquez, J. Asiain y S. Sierra cols. ”. Paratypes: Mexico: Chihuahua: “ Urique, Cerocahui, El Salitre, 1700 m, trampa de intercepción de vuelo, 9 a 12 - VII- 2006, M. Castillo y L. Delgado cols. ” (m 1, IEXA). Same data, except: “ El Dique, 1780 m, 18 a 21 - VII- 2006 ” (f 3, IEXA). Hidalgo “ Cardonal, El Boxo, bosque de encino, trampa de intercepción de vuelo, 20 a 27 - VII- 2019, Y. Buena col. ” (m 1, CC-UAEH). “ Huasca, ex Hacienda El Paraíso, localidad 2, bosque Juniperus - Quercus, trampa de intercepción de vuelo, 16 a 22 - VI- 2010, J. Asiain y J. Márquez cols. “ (1, CC-UAEH). “ Jacala de Ledezma, P. N. Los Mármoles, camino a Plomosas, bosque de pino-encino, 1811 m, N 20 ° 56 ’ 33.9 ”, W 99 ° 12 ’ 25.6 ”, en tronco con hongos, 20 - X- 2006, J, Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Santiago de Anaya, El Encinal, N 20 ° 26 ’ 56.0 ”, W 98 ° 55 ’ 20.5 ”, matorral xerófilo y encinos, trampa cebada con nopales fermentados, 22 a 29 - VII- 2018, F. M. Gómez I. S. Hernández cols. ” (1, MAAS). Same data as holotype (3, CC-UAEH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770B7F2481AFA362FAA5FF1D.taxon	description	Figs. 3 c, 12 e, n, 17 k, 18 j, 22 a, 28 b Total body length 12.3 mm. Black on head, antennae, mandibles, maxillary and labial palpi, pronotum, scutellum, coxae, trochanters and femora of anterior and middle legs, prosternum, anterior half of mesoventrite, sixth visible abdominal segment (except its anterior quarter that is reddish) and abdominal styli. Reddish on elytra, tibiae and tarsomeres of anterior and middle legs, posterior legs, posterior half of mesoventrite, metaventrite, visible abdominal segments 1 – 5 and anterior border of sixth. Head: transverse, with posterior corners convex; ratio length / width 0.66. Dorsal surface with punctures denser than in majority of species, but similarly distributed; sulcate longitudinal midline visible only in anterior third of cephalic length; front moderately foveate near anterior margin. Eyes more than 0.5 times the cephalic lateral length, not protruding at sides. Antennomeres 4 – 5 elongate, 6 – 10 transverse. Mandibles very long, 1.82 times longer than head; with two well separated teeth, basal tooth bigger than middle tooth; mandibular channel well developed, with external and internal margins well separated at base, internal margin carinate and forward reaching beyond level of middle tooth. Apical palpomere of maxillary palpi slightly longer than preapical palpomere; apical palpomere of labial palpi slightly more than 1.25 times longer than preapical palpomere. Head wider than pronotum (ratio 1.26). Neck in ventral view with microsculpture slightly coarser than that on head. Thorax: dorsal rows of pronotum each with five punctures; pronotum slightly longer than wide (ratio 1.06) and slightly wider at anterior corners than at posterior corners (ratio 1.09). Scutellum with punctures slightly denser and wider than on elytra, latter with moderately dense punctation. Prosternum slightly elevated before anterior margin, with a faint transverse carina. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, almost parallel to margin of intercoxal process, but not meeting it laterally, area above transverse discal ridge with rough microsculpture of wave lines. Profemur with external row of spines covering anterior 2 / 3 of its length, not reaching apex, basal spines small, increasing in size toward apex, but not very long; internal margin not discernible, with only some few small spines near apex (Fig. 12 e). Metatrochanter modified like slender hook, which is gradually curved toward apex where being strongly curved and acute, extending beyond 1 / 3, but less than 1 / 2 of length of posterior femur; metafemur curved at level of overlap with hook and slightly beyond; metatibia distinctly curved at inner part of anterior third. Tarsomeres moderately flattened dorsally. Abdomen: visible tergites 1 – 3 with posterior basal transverse carina well developed, adjacent area weakly depressed, narrow and almost smooth; first 2 or 3 visible tergites with some wide-superficial punctures combined with fine, sparse punctures; remaining tergites with moderately dense fine punctures. Visible sternites 1 – 4 with punctures denser than remaining sternites, distributed densely at sides and in basal half, and sparse in center of each sternite. Male pregenital sternite rounded at posterior margin, even faintly projected (Fig. 17 k). Male genital sternite short (2.42 times longer than wide), slightly asymmetrical, anterior portion occupying 55 % and posterior portion 45 % of its length, apical emargination deep (Fig. 18 j). Abdominal styli slender apically. Aedeagus: length 2.0 mm; oval-elongate shape; apex slender, subacute; basal half notably wider than apical half, mainly in lateral view; internal sac visible at apex (Fig. 22 a). Variability: in measurements and ratios: total body length in males 11.2 (range 9.5 – 12.0), in females 10.5 (range 9.5 – 11.4); ratio length / width of head in males 0.68 (range 0.63 – 0.82), in females 0.85 (range 0.81 – 0.88); ratio mandibular length / cephalic length in males 1.52 (range 1.00 – 1.74), in females 0.94 (range 0.92 – 1.00); ratio cephalic width / pronotal width in males 1.23 (range 1.12 – 1.29), in females 1.01 (range 0.96 – 1.10); ratio length / width of pronotum in males 1.09 (range 1.05 – 1.17), in females 1.17 (range 1.10 – 1.22); ratio anterior width / posterior width of pronotum in males 1.06 (range 1.02 – 1.10), in females 1.01 (range 1.00 – 1.07). Additionally, it was noted that in a few specimens the black color of the sixth visible abdominal segment covers a little more than the basal half, at most clearly exceeding basal half, but never the entire segment. Taxonomic comments: Belonuchus oxyporimimus may be confused with B. oxyporinus, because they share many characters, such as the color pattern of the body, also they can occur in sympatry; however, B. oxyporinus has only the coxae of anterior and middle legs black (which is the main difference between females); the intercoxal process of the mesoventrite is scutellum-shaped; the metatrochanter of males is modified like a hook in shape of a bottle opener, with a characteristic tooth at the base of its curvature; the pregenital sternite is straight or slightly emarginate at the posterior margin and the genital sternite and aedeagus are different. Belonuchus oxyporimimus, on the other hand, has the coxae, trochanters and femora of anterior and middle legs black; the intercoxal process of the mesoventrite is shield-shaped; males with metatrochanter modified like a hook that is not shaped like a bottle opener, but more elongate and without a basal tooth; the pregenital sternite of males is not emarginate at posterior margin, and the genital sternite and aedeagus are different.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770B7F2481AFA362FAA5FF1D.taxon	etymology	Etymology. The name refers to its close resemblance to B. oxyporinus.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789770B7F2481AFA362FAA5FF1D.taxon	materials_examined	Type material (115 males, 101 females): Holotype (male, CC-UAEH): “ México: Hidalgo, Zimapán, Parque Nacional Los Mármoles, Trancas, bosque de pino-encino, 2444 m, N 20 ° 48 ’ 12.22 ”. W 99 ° 14 ’ 41 ”, necrotrampa, 14 - IX al 13 - X- 2007, J. Márquez, J. Asiain y S. Sierra cols. ”. Paratypes: Mexico: Distrito Federal (now Mexico City): “ Xochimilco, 1.5 km S de San Andrés Ahuayucan, bosque de encino perturbado, 2450 m, NTP- 80 (calamar), 1 a 31 - VII- 1999, J. Márquez col. ” (14, MAAS). Guanajuato: “ km 8 carretera Guanajuato-Dolores, 2300 m, necrotrampa, 28 a 30 - V- 1995, L. Delgado col. ” (1, IEXA). “ Victoria, Puerto del Aire, km 32, N 21 ° 18.306 ’, W 100 ° 9.911 ’, bosque de encino, NTP- 80 (calamar), 13 a 16 - VII- 2009, M. Vargas y J. Márquez cols. ” (4, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo ” (1, CC-UAEH). “ Victoria, Puerto de Palmas, 1900 m, coprotrampa, 10 a 12 - VIII- 1999, L. Delgado y R. Arce cols. ” (3, IEXA). “ Xichú, km 36, después de Puerto del Aire, N 21 ° 18.743 ’, W 100 ° 08.253 ’, bosque de encino reforestado con pino, trampa de intercepción de vuelo, 13 a 16 - VII- 2009, M. Vargas y J. Márquez cols. ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) ” (1, CC-UAEH). Hidalgo: “ Acatlán, Loma Larga, El Llano, cultivos, matorral xerófilo y encinos, 2097 m, N 20 ° 16 ’ 13 ”, W 98 ° 28 ’ 18 ”, NTP- 80 (calamar), 13 al 20 - VII- 2010, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Cuatepec de Hinojosa, Tezoncualpan, El Campanario, bosque de pino-encino, 2724 m, NTP- 80 (calamar), 31 - XII- 2008 a 24 - I- 2009, M. Torres col. ” (1, CC-UAEH). “ Cuatepec de Hinojosa, Tezoncualpan, El Campanario, N 19 ° 57´13 ”, W 98 ° 16´31 ”, 2548 m, bosque de encino, trampa de intercepción de vuelo, 20 a 27 - VI- 2009, M. Torres col. ” (1, CC-UAEH). Same data, except: “ 22 a 29 - VIII- 2009 ” (1, CC-UAEH). Same data, except: “ 20 a 27 - II- 2010 ” (1, CC-UAEH). “ Epazoyucan, Ejido el Susto, bosque de pino-encino, 6 - VIII al 3 - IX- 2004, NTP- 80 (carne de cerdo), trampa 12, G. Pajas y J. Márquez cols. ” (1, CC-UAEH). “ Huasca, Rancho Santa Elena, bosque de pino encino, trampa de malaise, 2 - V a 3 - VI- 2003, I. Menchaca y A. Contreras cols. ” (1, CC-UAEH). “ Huasca de Ocampo, Rancho Santa Elena, bosque de pino encino, sitio DD, NTP- 80 (lagartija), 1 a 8 - VII- 2004, I. Castellanos, G. Sánchez y J. Márquez cols. ” (1, CC-UAEH). Same data, except: “ sitio CC, NTP- 80 (calamar) ” (1, CC-UAEH). Same data, except: “ sitio BB, NTP- 80 (pollo) ” (4, CC-UAEH). Same data, except: “ sitio O, NTP- 80 (ratón), 17 - VI a 1 - VII- 2004 ” (3, CC-UAEH). Same data, except: “ sitio I, NTP- 80 (pollo), 17 a 24 - VI- 2004 ” (2, CC-UAEH). Same data, except: “ sitio BB, NTP- 80 (pollo), 17 a 24 - VI- 2004 ” (3, CC-UAEH). Same data, except: “ sitio K, NTP- 80 (ratón), 1 a 8 - VII- 2004 ” (1, CC-UAEH). Same data, except: “ sitio CC, NTP- 80 (calamar), 17 - VI a 1 - VII- 2004 ” (1, CC-UAEH). Same data, except: “ sitio NN, NTP- 80 (pollo), 17 - VI a 1 - VII- 2004 ” (2, CC-UAEH). Same data, except: “ sitio L, NTP- 80 (pollo), 17 a 24 - VI- 2004 ” (1, CC-UAEH). Same data, except: “ sitio NN, NTP- 80 (pollo), 1 a 8 - VII- 2004 ” (1, CC-UAEH). Same data, except: “ sitio O, NTP- 80 (ratón), 17 a 24 - VI- 2004 ” (2, CC-UAEH). Same data, except: “ sitio L, NTP- 80 (pollo), 1 a 8 - VII- 2004 ” (1, CC-UAEH). Same data, except: “ sitio JJ, NTP- 80 (lagartija), 1 a 8 - VII- 2004 (1, CC-UAEH). Same data, except: “ 17 a 24 - VI- 2004 ” (1, CC-UAEH). Same data, except: “ sitio L, NTP- 80 (pollo), 17 - VI a 1 - VII- 2004 ” (2, CC-UAEH). Same data, except: “ sitio O, NTP- 80 (ratón), 1 a 8 - VII- 2004 ” (2, CC-UAEH). “ Huasca de Ocampo, Ocotillos, bosque de pino-encino, 2244 m, N 20 ° 12 ’ 1.6 ”, W 98 ° 36 ’ 42.6 ”, en hojarasca cernida, 26 - X- 2006, J. Márquez y J. Asiain cols. ” (2, MAAS). “ Huasca de Ocampo, Sta. María Regla, 3 km N, bosque de Juniperus- Quercus, en hongo podrido, 27 - VIII- 2014, J. Márquez col. ” (14, CC-UAEH). “ Huasca de Ocampo, cerca de Las Truchas, bosque de encino, 2168 m, en hojarasca, 27 - XII- 2001, J. Asiain y J. Márquez cols. ” (8, MAAS). “ La Misión, Lomas del Pericón, bosque mesófilo de montaña, 1377 m, N 21 ° 60 ’ 46.0 ”, W 99 ° 6.0 ’ 15.6 ”, trampa de intercepción de vuelo # 3, 26 - VIII a 9 - IX- 2011, J. Márquez col. ” (1, CC-UAEH). “ Omitlán de Juárez, bosque de encino, 2407 m, N 20 ° 9 ’ 45.0 ”, W 98 ° 38 ’ 3.9 ”, en hojarasca de riachuelo, 29 - III- 2003, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). Same data, except: “ necrotrampa NTP- 80 (calamar), 1 - II a 1 - III- 2003 ” (6, CC-UAEH). Same data, except: “ 1 a 29 - III- 2003 ” (18, CC-UAEH). Same data, except: “ 29 - III a 30 - IV- 2003 ” (32, CC-UAEH). Same data, except: “ 30 - IV a 29 - V- 2003 ” (18, CC-UAEH). Same data, except: “ 1 - V a 29 - VI- 2003 ” (3, CC-UAEH). Same data, except: “ 29 - VI a 30 - VII- 2003 ” (2, CC-UAEH). Same data, except: “ 29 - VII a 29 - VIII- 2003 ” (2, CC-UAEH). Same data, except: “ en hongos podridos, 30 - VII- 2003 ” (2, CC-UAEH). Same data, except: “ 31 - X- 2003 ” (3, CC- UAEH). Same data, except: “ 29 - XII- 2003, en nopales podridos ” (2, CC-UAEH). “ Santiago de Anaya, El Encinal, N 20 ° 26 ’ 56.0 ”, W 98 ° 55 ’ 20.5 ”, matorral xerófilo y encinos, trampa cebada con nopales fermentados, 24 - VI a 1 - VII- 2018, F. M. Gómez I. S. Hernández cols. ” (1, CC-UAEH). “ Zempoala, Mina San Juan Tepemazalco, matorral xerófilo, 2200 m, N 19 ° 54 ’ 25.4 ” W 98 ° 43 ’ 44.4 ”, semana 4, 4 al 30 - IV- 2007, NTP- 80 (carne de cerdo), trampa 4, Z. Huerta y J. Márquez cols. ” (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, camino a Nicolás Flores, bosque de encino, 2444 m, N 20 ° 48 ’ 12.2 ”, W 99 ° 14 ’ 42 ”, en coprotrampa, 29 al 23 - VI- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (2, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Minas Viejas, bosque de encino, 1892 m, N 20 ° 55 ’ 5.2 ”, W 99 ° 12 ’ 41.1 ”, coprotrampa, 20 - IX al 11 - X- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (1, CC-UAEH). “ P. N. Los Mármoles, Zimapán, La Encarnación, bosque de encino, 2412 m, N 20 ° 52 ’ 1 ” W 99 ° 12 ’ 50.3 ”, en excremento, 23 - VI- 2007, J. Márquez y J. Asiain cols. ” (15, CC-UAEH). Same data, except: “ coprotrampa, 30 - V al 23 - VI- 2007 ” (3, CC-UAEH). “ P. N. Los Mármoles, Zimapán, La Encarnación, bosque de pino-encino, 2412 m, N 20 ° 51 ’ 55.6 ”, W 99 ° 12 ’ 38.5 ”, NTP- 80 (calamar), 23 - VI al 13 - VII- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (5, CC-UAEH). “ P. N. Los Mármoles, Minas Viejas, bosque de encino, 1892 m, N 20 ° 55 ’ 5.2 ”, W 99 ° 12 ’ 41.1 ”, NTP- 80 (calamar), 13 al 18 - VIII- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (1, CC-UAEH). “ Zimapán, El Salto a 2 km al E de Durango, 14 Q 0477652, UTM 231197, bosque de encino, 2153 m, NTP- 80 # 3, 28 - III a 04 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Trancas, bosque de pino-encino, 2444 m, N 20 ° 48 ’ 12.22 ”, W 99 ° 14 ’ 41 ”, coprotrampa, 22 - VI al 12 - VII- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (3, CC-UAEH). Same data, except: “ 22 - VI al 12 - VII- 2007 ” (2, CC-UAEH). Morelos: “ Tlayacapan, San José de los Laureles, N 18 ° 58 ’ 6.37 ”, W 99 ° 00 ’ 8.02 ”, 2156 m, bosque de pino-encino, zona 1, en excremento caballar, 15 - I- 2000, J. Asiain y J. Márquez cols. ” (2, MAAS). Oaxaca: “ La Cascada, camino a El Vergel, bosque de encino, 1917 m, N 16 ° 50 ’ 46.6 ”, W 97 ° 34 ’ 47.5 ”, NTP- 80 (calamar), 10 a 13 - VII- 2005, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Ixtlán de Juárez, km 152 a Tuxtepec, bosque de pino-encino, 1923 m, 16 - XI- 1999, en excremento vacuno, J. Márquez col. ” (1, MAAS). Veracruz: “ Coscomatepec, Tecoac, bosque mesófilo de montaña, 1750 msnm, NTP- 80 (calamar) # 754, 3 - VI a 1 - VII- 1995, M. A. Pensado y Q. Santiago cols. ” (1, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977087F2B81AFA703FC95F8A9.taxon	description	Figs. 3 e, f, 11 b, 12 f, o, 15 b, 18 k, 22 b, 27 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977087F2B81AFA703FC95F8A9.taxon	description	Head: transverse in males (ratio length / width 0.70, range 0.67 – 0.77) and in females (ratio 0.83, range 0.80 – 0.89). Dorsal surface with sulcate longitudinal midline visible in anterior half of head and front narrowly foveate near anterior margin. Eyes almost 0.5 times the cephalic lateral length, not protruding laterally. Antennomeres 4 – 5 elongate, 6 – 10 transverse. Males with mandibles longer than head (ratio 1.37, range 1.17 – 1.53); females with mandibles almost as long as head (propotion 1.03, range 0.93 – 1.18); mandibles with two widely separated teeth (basal and middle); mandibular channel well developed, with external and internal margins widely separated at base, internal margin carinate, extending forward beyond level of middle tooth. Apical palpomere of maxillary palpi slightly longer than preapical palpomere; apical palpomere of labial palpi at least 1.25 times longer than preapical palpomere. Head of males wider than pronotum (ratio 1.25, range 1.18 – 1.32), in females almost equally wide (ratio 1.05, range 0.97 – 1.08). Thorax: dorsal rows of pronotum each with five punctures; pronotum almost as long as wide in both sexes (ratio in males 1.07, range 1.03 – 1.09, in females 1.12, range 1.06 – 1.15); and almost as wide at anterior corners as at posterior corners (ratio in males 1.03, range 1.00 – 1.06, in females 1.00, range 0.94 – 1.01). Scutellum and elytra with fine, moderately dense punctures and setae. Prosternum slightly elevated behind anterior margin, in some large males, a faint transverse carina is visible. Intercoxal process of mesoventrite scutellum-shaped; transverse discal ridge well defined, broadly V-shaped, not meeting margins of intercoxal process laterally (Fig. 11 b). Profemur of males with external row of spines in no more than its anterior half (Fig. 12 f), not reaching apex, basal spines small, increasing in size toward apex, but not considerably; internal margin not discernible, with only some short spines near apex. Metatrochanter of males modified like a hook, spine-like in small males proportionately increasing in size with size of specimens, in large specimens the apex of hook resembling a bottle opener, with a tooth or spine at base of its curvature; in large specimens the length of hook covers more than 1 / 3, but less than 1 / 2 of length of metafemur (Fig. 12 – o); metafemur not curved at level of its overlap with the hook, or only weakly curved in larger specimens; metatibia curved at inner part near its apical third only in large specimens, curvature becoming gradually less visible in proportion with the reduction of size of specimens. Tarsomeres moderately flattened dorsally. Abdomen: visible tergites 1 – 3 with posterior basal transverse carina well developed, adjacent area slightly to moderately depressed, this area and entire surface of tergites with fine, sparse punctures. Sternites with some widesuperficial punctures combined with fine, sparse punctures. Male pregenital sternite not emarginate at posterior margin (Fig. 15 b). Male genital sternite short (2.15 times as long as wide), very asymmetrical, anterior portion occupying 39 % and posterior portion 61 % of its length, apical sinuation very deep (Fig. 18 k). Abdominal styli slender, slightly flattened at rounded apex. Aedeagus: length 1.7 mm; oval-elongate shape; apex convex in ventral view and slightly acute in lateral view; with some fine setae in apical posterior part; in ventral view, basal half moderately wider than apical half, in lateral view, basal half notably wider than apical half; internal sac visible in apical third (Fig. 22 b). Variability. In addition to the measurements and ratios indicated in the description, and those related to the size of the males, as well as the differences according to sex, the number of punctures in the dorsal rows on pronotum can vary: 5: 6, 6: 5, 4: 5, 5: 4; the sixth visible abdominal segment at most is black in the basal half and reddish in the apical half, but in specimens mounted without stretching that segment well, it gives the appearance of having more than the basal half black. Some specimens have few wide-superficial punctures on visible tergites 1 – 2. Taxonomic comments. This species is very similar to B. oxyporimimus, in the taxonomic comments of that species it was indicated how to distinguish them. The female holotype of this species was not studied, but we analyzed some photos of this specimen (Fig. 3 e; NHM, shared by M. Chani Posse), which together with the information of the original description (Sharp 1885) allowed us to identify this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977087F2B81AFA703FC95F8A9.taxon	materials_examined	Material examined (184 males, 257 females): Mexico: Chihuahua: “ Urique, Cerocahui, 1750 m, 18 a 21 - VII- 2006, M. Castillo y L. Delgado cols. ” (2, IEXA). Guerrero: “ Palo Blanco, Sierra del Alquitrán, 1670 m, necrotrampa, 27 a 29 - IX- 1999, L. Delgado col. ” (1, IEXA). Michoacán: “ autopista México-Morelia, km 194, bosque de encino, 2180 m, en hongos podridos, 20 - IX- 2001, J. Márquez col. ” (4, MAAS). “ Los Azufres, km 4 carretera Los Azufres-Ciudad Hidalgo, ex hongo, J. A. Gómez col. ” (1, IEXA). Morelos: “ Cuernavaca, camino a Mexicapa, bosque de pino-encino, 2300 m, NTP- 80 (calamar) # 1, mayo de 1993, J. Márquez, E. Córdoba, A. Soria y C. Cabello cols. ” (3, MAAS). Same data, except: “ junio de 1993 ” (5, CC-UAEH; 5, MAAS). Same data, except: “ julio de 1993 ” (5, MAAS). Same data, except: “ noviembre de 1993 ” (5, MAAS). Same data, except: “ NTP- 80 (calamar) # 2, 14 - VIII- 1993 ” (5, MAAS). Same data, except: “ 12 - IX- 1993 ” (3, MAAS). Same data, except: “ octubre de 1993 ” (11, CC-UAEH). Same data, except: “ 3 - X- 1993 ” (4, MAAS). Same data, except: “ febrero de 1994 ” (12, MAAS). Same data, except: “ NTP- 80 (calamar) # 3, 5 - IX- 1992 ” (1, MAAS). Same data, except: “ julio de 1993 ” (1, MAAS). Same data, except: “ octubre de 1993 ” (2, MAAS). Same data, except: “ febrero de 1994 ” (1, MAAS). Same data, except: “ NTP- 80 (calamar) # 4, 24 - IV- 1993 ” (1, MAAS). Same data, except: “ agosto de 1993 ” (1, MAAS). Same data, except: “ septiembre de 1993 ” (2, MAAS). Same data, except: “ 24 - X- 1993 ” (7, CC-UAEH; 7, MAAS). Same data, except: “ noviembre de 1993 ” (20, CC-UAEH; 39, MAAS). Same data, except: “ febrero de 1994 ” (17, MAAS). Same data, except: “ NTP- 80 (calamar) # 5, 5 - IX- 1992 ” (5, MAAS). Same data, except: “ 3 - X- 1992 ” (1, MAAS). “ febrero de 1993 ” (1, MAAS). Same data, except: “ 11. VII- 1993 ” (5, MAAS). Same data, except: “ agosto de 1993 ” (7, MAAS). Same data, except: “ septiembre de 1993 ” (2, MAAS). Same data, except: “ octubre de 1993 ” (7, MAAS). Same data, except: “ NTP- 80 (calamar) # 6, junio de 1993 ” (9, MAAS). Same data, except: “ noviembre de 1993 ” (2, MAAS). Same data, except: “ febrero de 1994 ” (2, MAAS). “ Mexicapa, bosque de pino, zona 1, ex NTP- 80 calamar, 25 - IV- 1993, A. Soria, C. Cabello y E. Córdoba cols. ” (1, MAAS). “ Cuernavaca, Santa María Ahuacatitlán, bosque mesófilo de montaña, 2000 m, en hongos, 30 - VII- 1996, L. Delgado col. ” (1, QJSJ). “ Tlayacapan, San José de los Laureles, localidad 1, bosque de pino-encino, NTP- 80 (calamar), agosto de 1995, J. Márquez col. ” (20, CC-UAEH; 25, MAAS). Same data, except: “ K. Villavicencio y J. Márquez cols. ” (1, MAAS). Same data, except: “ septiembre de 1995, J. Márquez col. ” (4, MAAS). Same data, except: “ octubre de 1995 ” (26, MAAS). Same data, except: “ septiembre de 1996 ” (10, CC-UAEH; 26, MAAS). Same data, except: “ localidad 2, bosque de pino, agosto de 1995 ” (1, MAAS). Same data, except: “ septiembre de 1995 ” (1, MAAS). Same data, except: “ junio de 1996 ” (1, MAAS). Same data, except: “ diciembre de 1996 ” (1, MAAS). Same data, except: “ localidad 3, bosque mesófilo de montaña, marzo de 1993 ” (1, MAAS). Same data, except: “ julio de 1995 ” (3, MAAS). Same data, except: “ septiembre de 1995 ” (8, MAAS). Same data, except: “ octubre de 1995 ” (13, MAAS). Same data, except: “ noviembre de 1996 ” (1, MAAS). Same data, except: “ en hongos diversos, 15 - VIII- 1998, R. Toledo y J. Márquez cols. ” (3, MAAS). Same data, except: “ en hojarasca, 28 - V- 2000, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). Same data, except: “ localidad 4, bosque tropical caducifolio, agosto de 1996, J. Márquez col. ” (12, MAAS). Oaxaca: “ Ixtlán de Juárez, km 152 a Tuxtepec, N 17 ° 20.623´, W 96 ° 30.92´, bosque de pino-encino, 1923 m, 16 - XI- 1999, en excremento vacuno, J. Márquez col. ” (1, MAAS). Same data, except: “ en hongo podrido ” (2, MAAS). “ 1.5 km NE de San José del Pacífico, 2248 m, bosque de pino-encino, sobre hongos Amanita, 8 - VII- 2002, J. Asiain y J. Márquez cols. ” (3, MAAS). “ Santiago Yosondua, camino a Santa María Yolotepec, N 16 ° 51´13 ”, W 97 ° 33´43.6 ”, 2398 m, bosque de pino-encino, en hongos, 10 - VII- 2005, J. Asiain y J. Márquez cols. ” (52, CC-UAEH). Same data, except: “ camino a El Vergel, La Cascada, bosque de encino, en hongos, 9 - VIII- 2001, J. Asiain, S. Bautista y J. Márquez cols. ” (1, MAAS). “ Santiago Yosondua, La Cascada, bosque de encino, 1917 m, N 16 ° 50 ’ 49.6 ”, W 97 ° 34 ’ 47.5 ”, en Boletus sp., 10 - VI- 2005, J. Márquez y J. Asiain cols ” (6, CC-UAEH). Veracruz: “ Coscomatepec, Tecoac, bosque mesófilo de montaña, 1750 m, ex NTP- 80 (calamar) # 754, 3 - VI a 1 - VII- 1995, M. A. Pensado y Q. Santiago cols. ” (1, MAAS; 2, QJSJ). Same data, except: “ 23 - IX a 21 - X- 1995 ” (1, QJSJ). Same data, except: “ 6 - V a 3 - VI- 1995 ” (2, QJSJ). Same data, except: “ 8 - IV a 6 - V- 1995 ” (2, QJSJ).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977067F2981AFA6ABFDB6FEA5.taxon	description	Figs. 3 d, 17 – l, 18 – l, 22 c, 28 b Total body length 12.8 mm. Body almost completely black, except elytra and legs which are reddish (excluding coxae that are black). On some parts of antennae, mandibles, maxillary and labial palpi, coxae, scutellum and abdominal segments, the black color appears as dark-brown or reddish-brown. Elytra with setiferous punctures somewhat dark color. Abdominal sternites darker in basal half and reddish-brown in apical half. Head: transverse, ratio length / width 0.68, slightly convex dorsally and at posterior corners. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front with a circular foveate area between antennal insertions. Eyes slightly less than 0.5 times the cephalic lateral length, not protruding laterally. Antennomere 4 slen- der and elongate, 5 – 7 elongate, 8 – 10 transverse. Mandibles 1.42 times longer than head; with two well separated teeth (basal and middle), basal tooth bigger than a middle tooth; mandibular channel well developed, external and internal margins well separated at base, the latter being carinate at base and extending like impressed line slightly beyond level of middle tooth. Apical palpomere of maxillary and labial palpi near 1.25 times longer than preapical palpomere. Ventral surface convex, with a depressed stripe parallel to anterior margin below mouth parts and with some sparse fine punctures. Head 1.3 times wider than pronotum. Neck with wrinkled microsculpture ventrally. Thorax: pronotum with five punctures in each dorsal row; slightly longer than wide (ratio 1.1), almost as wide at anterior corners as at posterior corners (ratio 1.05). Scutellum with punctures denser than on elytra; elytra with setiferous punctures moderately dense. Prosternum with anterior margin depressed, followed by an elevated zone which ends like small arc. Intercoxal process of mesoventrite shield-shaped, transverse discal ridge diffusely visible, slightly rounded. Metaventrite very glossy, longitudinal midline not visible, with sparse setae in center and toward sides. Procoxae dark in external half and reddish in internal half; profemur with external row of spines initiating in basal third and reaching near 3 / 4 of its length, basal spines smaller and more spaced than spines at middle part and near the apex; internal margin with few spines near apex. Metatrochanter modified like a big, elongate hook, as long as, or slightly longer than 1 / 2 length of metafemur, its apex strongly curved and directed toward internal part of body; metafemur not flattened or curved at level of overlap with hook; metatibia slightly curved in anterior third. Tarsomeres flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed, adjacent area weakly depressed, covered with sparse punctures, which are slightly wider than punctures on remaining tergites and all sternites, where punctures are fine and sparse. Male pregenital sternite with posterior margin with small U-shaped emargination, and slightly convex at each side of it (Fig. 17 – l). Male genital sternite short (2.44 times longer than wide), slightly asymmetrical, anterior portion occupying 52 % and posterior portion 48 % of its length, apical emargination very deep (Fig. 18 – 1). Abdominal styli very slender. Aedeagus: length 2.2 mm; oval-elongate shape; apex somewhat acute, spine-shaped; base rounded; in ventral view, basal half moderately wider than apical half, most notable in lateral view; internal sac visible in anterior half (Fig. 22 c). Variability. The female has mandibles, head and pronotum black, shiny; abdomen and sterna irregularly dark brown to black; legs reddish-brown, with coxae dark-brown. The transverse discal ridge of the mesoventrite is better developed and is a little acute, projecting posteriad. Metaventrite with dense setae. Abdomen with fine, sparse punctures. Total body length 13.2 mm; ratio length / width of head 0.81; ratio mandibular length / cephalic length 1.18; ratio cephalic width / pronotal width 1.23; ratio length / width of pronotum 1.11; ratio anterior width / posterior width of pronotum 1.03. One studied male specimen from Guatemala (El Progreso) with a total body length 14.9 mm; ratio length / width of head 0.65; ratio mandibular length / cephalic length 1.7; ratio cephalic width / pronotal width 1.41; ratio length / width of pronotum 1.07; ratio anterior width / posterior width of pronotum 1.07. Antennomeres 1 – 9 almost black and 10 – 11 reddish-brown; procoxae clearly bicolored; mesoventrite with transverse discal ridge slightly visible; abdominal styli elongate and slightly widened at apex. Taxonomic comment. This species is very similar to B. julietitae. See taxonomic comments for that species on how to distinguish them.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977067F2981AFA6ABFDB6FEA5.taxon	etymology	Etymology. The name refers to the beauty that this species possesses, with its lustrous reddish legs and elytra that are contrasting with the black color of the rest of the body.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977067F2981AFA6ABFDB6FEA5.taxon	materials_examined	Type material (two males, one female): Holotype (male, CC-UAEH): “ Guatemala: El Progreso, Sierra de Las Minas, Pinalón, N 15.0754 °, W 89.94717 °, 2236 m, bosque nuboso, en hojarasca cernida, 29 - V- 2014, M. Barrios col. ”. Paratypes: México: Chiapas: “ 9 km W San Cristóbal, hwy 190, (2390 m), oak-pine forest, 29 June 1979 / FMHD # 79 - 305 ex leaf litter, J. S. Ashe (m 1, FMNH) ”. “ San Cristóbal de las Casas (4 mi W), 7900 ft., 16 ° 43 ’ N, 92 ° 42 ’ W, 30 - VIII- 1973, pine-oak-madroño forest / mushroom trap (rotting), A. Newton 544 F, FMHD # 73 - 1122, Field Museum N. H. ” (f 1, FMNH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977057F2881AFA7AEFB06F991.taxon	description	Figs. 3 g, 11 c, 15 k, 18 m, 22 d, 26 b Total body length 12.05 mm. Black on head, antennae, pronotum, scutellum, posterior 2 / 3 of sixth visible abdominal segment and abdominal styli. Reddish on elytra, mesoventrite, metaventrite, legs, first five visible abdominal segments and anterior third of sixth. Brown on mandibles (irregularly), maxillary and labial palpi, prosternum and genital segment. Head: transverse, ratio length / width 0.74. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front foveate between antennal insertions. Eyes nearly 0.5 times the cephalic lateral length, not protruding laterally. Antennomeres 4 – 5 elongate, 6 as long as wide, 7 – 10 transverse. Mandibles 1.3 times longer than head; each with two teeth, basal tooth notably bigger than middle tooth; mandibular channel well developed, external and internal margins moderately separated at base, internal margin carinate, extending forward beyond level of middle tooth. Apical palpomere of maxillary and labial palpi almost 1.25 times longer than preapical palpomere. Head 1.3 times wider than pronotum. Thorax: each dorsal row of pronotum with six punctures; pronotum slightly longer than wide (ratio 1.09) and slightly wider at anterior corners than at posterior corners (ratio 1.1). Scutellum with punctures denser than on elytra, latter with moderately dense punctation. Prosternum with area adjacent to anterior margin elevated and delimited behind by a transverse, slightly depressed line. Intercoxal process of mesoventrite shield-shaped, its apex acute, slightly acuminate; transverse discal ridge slightly visible, not meeting margin of intercoxal process laterally (Fig. 11 c). Profemur with external row of spines initiating near basal third, spines small to medium sized, sparse, before apex with a space without spines, as if one or two spines were missing, and ending at apex with one or two spines; with four to five apical spines at internal margin longer than external spines. Metatrochanter modified like a hook, elongate at base, but at apex making a 90 - degree turn to end in acute downward point, longer than 1 / 3 and shorter than 1 / 2 the length of metafemur; metafemur with internal margin curved at level of overlap with hook and slightly beyond; metatibia with internal side curved in anterior third. Tarsomeres flattened dorsally. Abdomen: first three visible abdominal tergites with posterior basal transverse carina well developed, adjacent area slightly depressed, with wide-superficial punctures denser at sides than at center, on remaining surface only with fine, moderately dense punctures; visible tergite 4 with wide-superficial punctures denser in anterior half than in posterior half, in latter area combined with fine punctures which cover also the remaining tergites. Visible sternites 1 – 4 with wide-superficial punctures denser than on tergites, combined with fine punctures; remaining sternites with both types of punctures, but few dense. Male pregenital sternite with weak, broadly arcuate emargination at posterior margin (Fig. 15 k). Male genital sternite moderately elongate (2.58 times longer than wide), very asymmetrical, anterior portion occupying 35 % and posterior portion 65 % of its length; apical emargination very deep (Fig. 18 m). Abdominal styli slender. Aedeagus: length 1.5 mm; elongate shape; apex moderately acute; sides converging almost homogeneously from base to apex; basal half moderately wider than apical half; internal sac visible (Fig. 22 d). Variability. Total body length in males 11.0 mm (range 8.9 – 12.1 mm), in females 10.8 mm (range 9.8 – 11.7 mm); ratio length / width of head in males 0.77 (range 0.7 – 0.85), in females 0.85 (range 0.81 – 0.89); ratio mandibular length / cephalic length in males 1.56 (range 1.33 – 1.83), in females 0.82 (range 0.72 – 0.92); ratio cephalic width / pronotal width in males 1.23 (range 1.09 – 1.33), in females 1.09 (range 1.06 – 1.14); ratio length / width of pronotum in males 1.13 (range 1.11 – 1.2), in females 1.15 (range 1.10 – 1.21); ratio anterior width / posterior width of pronotum in males 1.02 (range 0.91 – 1.07), in females 1.01 (range 1.00 – 1.07); aedeagus length 1.32 (1.25 – 1.4). In smaller males, the posterior trochanters are very similar to those of females, with only a small apical spine. The apical antennomere may be lighter than the previous ones. The number of punctures in the dorsal rows of pronotum varies by one or maximum two punctures more or less than the normal six. The sixth visible abdominal segment usually has the basal 2 / 3 black and 1 / 3 reddish, but the reddish part can occupy up to about 1 / 2. Taxonomic comments. Belonuchus rufisternus was separated from B. apiciventris after extensive review of the material, and in previous publications where the studied specimens were included, they were not distinguished. Therefore, the species with which B. rufisternus can be most confused is B. apiciventris and its main differences can be found under taxonomic comments for that species. It may also be confused with B. tepoztecus due to its great similarity in size and color pattern but they can be distinguished using the taxonomic comments of the latter species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977057F2881AFA7AEFB06F991.taxon	etymology	Etymology. The name is a combination of “ rufus ” and “ sternum ”, which refers to the reddish color of the mesoventrite and helps to distinguish it from B. apiciventris, which has a black mesoventrite.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977057F2881AFA7AEFB06F991.taxon	materials_examined	Type material (68 males, 56 females): Holotype (male, CC-UAEH): “ México: Morelos, Tlayacapan, camino a Santa Catarina, Loc. 4, N 18 ° 57 ’ 13 ”, W 99 ° 00 ’ 15 ”, selva tropical caducifolia, 1550 m, NTP- 80, 1 a 30 - XII- 1996, J. Márquez col. ”. Paratypes: Mexico: Chiapas: “ carretera Tuxtla Gutiérrez-San Cristobal de las Casas, km 30.7, selva mediana perturbada, 961 m, N 16 ° 45 ’, W 92 ° 57 ’, NTP- 80 calamar, 20 - IX al 3 - XII- 1999, J. Márquez col. ” (m 2, f 3, MAAS). Morelos: “ Cuernavaca, camino a Mexicapa, bosque de pino, NTP- 80 calamar, Zona 1, 25 - IV- 1993, A. Soria, C. Cabello y E. Córdoba cols. ” (f 1, MAAS). Same data, except: “ 1 a 30 VI- 1993 ” (f 2, MAAS). “ Tepoztlán, Ocotitlán, Cueva del Diablo, 20 - XII- 1977, L. Jiménez ” (m 2, MAAS). Same data, except: “ 20 - XII- 1977, R. Badillo ” (m 1, f 1, MAAS). Same data, except: “ C. Martínez ” (m 3, MAAS). Same data, except: “ 7 - I- 1977, J. Palacios ” (m 1, f 1, MAAS). Same data, except: “ 4 - XII- 1977 ” (f 1, MAAS). Same data, except: “ 4 - VI- 1978, M. Ortíz ” (m 1, MAAS). Same data, except: “ 21 - V- 1978, M. R. Martínez ” (m 2, MAAS). Same data, except: “ 17 - VI- 1978, C. Valdez ” (m 1, MAAS). Same data, except: “ 20 - XII- 1977, G. Meneses ” (m 1, MAAS). Same data, except: “ 15 - X- 1977, D. López ” (f 1, MAAS). Same data, except: “ 1 - XII- 1977, M. Morales ” (f 1, MAAS). Same data, except: “ 20 - XII- 1977, J. Vázquez ” (f 1, MAAS). Same data, except: “ 21 - V- 1978, A. García ” (f 1, MAAS). Same data, except: “ 21 - V- 1978, M. E. Vera ” (f 1, MAAS). Same data, except: “ 4 - VI- 1978 ” (f 1, MAAS). Same data, except: “ 21 - V- 1978, G. Muños ” (f 1, MAAS). Same data, except: “ 4 - VI- 1978, G. Borja ” (f 1, MAAS). “ Tlayacapan, San José de los Laureles, Loc- 1, N 18 ° 58 ’ 33 ”, W 99 ° 00 ’ 47 ”, 2000 m, bosque de pino-encino, NTP- 80 (calamar), 1 - 30 - X- 1995, J. Márquez col. ” (f 1, MAAS). Same data, except: “ Loc- 3, N 18 ° 58 ’ 29 ”, W 99 ° 01 ’ 25 ”, 1700 m, bosque mesófilo de montaña, NTP- 80, 1 a 30 - XII- 1995, J. Márquez col. ” (m 13, f 5, MAAS). Same data, except: “ 1 a 30 - X- 1995 ” (m 2, CC-UAEH). Same data, except: “ 1 - 30 - IV- 1996 ” (m 1, f 2, MAAS). Same data, except: “ 1 a 30 - VIII- 1996 ” (m 1, CC-UAEH). Same data, except: “ 1 a 30 - XI- 1996 ” (m 3, f 4, MAAS). Same data, except: “ 1 a 30 - I- 1996 ” (m 3, CC-UAEH). Same data, except: “ 1 a 30 - VI- 1996 ” (m 1, CC-UAEH). “ Tlayacapan, camino a Santa Catarina, N 18 ° 57´13 ”, W 99 ° 00´15 ”, 1550 m, Loc- 4, selva tropical caducifolia, 1 - 30 - VII- 1995, K. Villavicencio y J. Márquez cols. ” (m 1, MAAS). Same data, except: “ 1 - 30 - VIII- 1995 ” (m 1, MAAS). Same data, except: “ 1 - 30 - X- 1995 ” (m 1, f 2, MAAS). Same data, except: “ 1 - 30 - XI- 1995 ” (f 2, MAAS). Same data, except: “ 1 - 28 - II- 1996 ” (f 1, MAAS). Same data, except: “ 1 - 30 - IX- 1996 ” (f 1, MAAS). Same data, except: “ 1 - 30 - XII- 1996 ” (m 7, f 2, MAAS). Same data, except: “ 1 a 30 - III- 1996 ” (m 2, CC-UAEH). Same data, except: “ 1 a 30 - VIII- 1996 ” (m 3, CC-UAEH). Same data, except: “ 1 a 30 - IV- 1996 ” (m 2, CC-UAEH). Same data, except: “ 1 a 30 - IX- 1996 ” (m 5, CC-UAEH). Same data, except: “ 1 a 30 - V- 1996 ” (m 1, CC-UAEH). Same data, except: “ 1 a 30 - I- 1996 ” (m 1, CC-UAEH). Same data, except: “ 1 a 30 - II- 1996 ” (m 2, CC-UAEH). “ Tlayacapan, N 18 ° 58 ’ 29 ”, W 99 ° 01 ’ 44 ”, 1685 m, Loc- 5, cultivos de temporal, NTP- 80, 1 a 30 - IX- 1996, J. Márquez col. ” (m 2, CC-UAEH). Oaxaca: “ Candelaria Loxicha, Portillo del Rayo, Finca Dos Ángeles, 1100 m, bosque tropical y cafetal, NTP, VI- 1990, C. Deloya López col. / IEXA 5320261 ” (m 1, IEXA). Same data, except: “ Finca El Encanto, 750 m / IEXA 5320261 ” (m 1, IEXA).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977047F2F81AFA087FED5FAB1.taxon	description	Figs. 3 h, 10 b, 14 a, e, 17 g, 18 n, 22 e, 26 b Total body length 11.2 mm. The only known specimen might be teneral, thus, what is indicated here as reddishbrown could be black. Reddish-brown on head, antennae, mandibles, neck, pronotum and prosternum. Third and fourth visible abdominal segments irregularly reddish-brown, with some borders lighter. Reddish on maxillary and labial palpi, elytra, scutellum, mesoventrite, metaventrite, legs, visible abdominal segments 1 – 2 and 5 – 6, genital segment and styli. Head: transverse, ratio length / width 0.62. Dorsal surface with central part of front notably foveate, fovea crossed by sulcate longitudinal midline of head, this later is clearly visible in the fovea and slightly visible backward (Fig. 10 b). Eyes slightly more than 0.5 times the cephalic lateral length, slightly protruding at sides. Antennomere 4 elongate, 5 almost as long as wide, 6 – 10 transverse. Mandibles very long, 1.7 times longer than head; with a basal tooth and a middle tooth, widely separated; mandibular channel well developed, with external margin well separated from internal margin at base, internal margin carinate, extending beyond level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.5 times longer than preapical palpomere. Head 1.35 times wider than pronotum. Neck with moderate wrinkled microsculpture ventrally. Thorax: left dorsal row of pronotum with five punctures and right dorsal row with six punctures; pronotum almost as long as wide (ratio 1.03) and slightly wider at anterior corners than at posterior corners (ratio 1.1). Scutellum with dense punctures, slightly wide and superficial. Elytra with similar punctures as on scutellum, but slightly less dense. Prosternum with an elevated transverse zone near to anterior margin. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge irregular, slightly acute posteriorly. Profemur with external row of spines initiating distant from base and ending distant from apex, spines not dense and of moderate size; internal margin with few spines only near apex. Metatrochanter modified like a hook that is projected until near 1 / 2 of length of metafemur; metafemur flattened to slightly convex at area of overlap with hook; metatibia curved on internal margin, near midlength. Tarsomeres flattened dorsally. Abdomen: first visible tergite with posterior basal transverse carina well developed, visible tergites 2 – 3 with posterior basal transverse carina somewhat faint; depressed adjacent zone well developed, with dense wide-superficial punctures; remaining parts of abdomen only with fine, moderately dense punctures (Fig. 14 a). Male pregenital sternite with distinct V-shaped emargination at posterior margin (Fig. 17 g). Male genital sternite short (2.33 times longer than wide), moderately asymmetrical, anterior portion occupying 40 % and posterior portion 60 % of its length, apical emargination deep and wide (Fig. 18 n). Abdominal styli moderately wide. Aedeagus: length 1.6 mm; elongate shape; apex wide and convex, sides slightly narrowed in anterior third and then gradually widened towards base; basal half moderately wider than apical half; internal sac visible (Fig. 22 e). Variability. Could not be assessed due to availability of only one specimen. Taxonomic comments. Due the color pattern of the abdomen, combining reddish and dark-reddish segments, this species resembles some species of Paederomimus. This is the only Mexican species of Belonuchus with the third and fourth visible abdominal segments dark and fifth and sixth segments pale, all the other species with dark segments have them apically.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977047F2F81AFA087FED5FAB1.taxon	etymology	Etymology. The name refers to the fact that only a single specimen of this species was available.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977047F2F81AFA087FED5FAB1.taxon	materials_examined	Type material: Holotype (male, FMNH): “ México, Oaxaca, 12 mi S de Valle Nacional, 3200 ft, 17 ° 41 ’ N, 96 ° 19´W, 22 - 31 - VII- 1971 / tropical subevergreen forest, carrion trap (squid), A. Newton, 302 Cs / Belonuchus det. Newton, 1995 ”.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977037F2E81AFA3A7FAEBF8CD.taxon	description	Figs. 4 a, 13 b, 15 – l, 18 – o, 22 f, 28 a Total body length 10.8 mm. Black on head, antennomeres 1 – 3, borders of mandibles, pronotum, scutellum, posterior half of prosternum, entire sixth and anterior half of fifth visible abdominal segments, and abdominal styli. Reddish on elytra, legs, anterior half of prosternum, posterior half of mesoventrite, entire metaventrite, visible abdominal segments 1 – 4 and anterior half of fifth. Brown on antennomeres 4 – 11 and mesoventrite. Head: transverse, slightly convex at sides and backward; ratio length / width of head 0.73. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front foveate in a small portion near to anterior margin. Eyes nearly 0.5 times the cephalic lateral length, not protruding laterally. Antennomeres 4 – 6 elongate, 7 – 10 almost as long as wide. Mandibles 1.5 times longer than head; each with two widely separated teeth (basal and middle) of moderate size; mandibular channnel with external margin expanded at basal third of its length, leaving a wide space between this and internal margin, which is carinate and ends near level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Head 1.29 times wider than pronotum. Thorax: pronotum with five punctures in the left and seven in the right dorsal row; pronotum slightly longer than wide (ratio 1.1) and almost as wide at anterior corners as at posterior corners (ratio 1.07). Scutellum with punctures slightly denser than on elytra, its margins smooth. Elytra with punctures moderately dense, with fine setae. Prosternum moderately elevated behind anterior margin. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge clearly visible, broadly U-shaped or V-shaped, slightly acute posteriorly, meeting margin of intercoxal process laterally. Profemur with external row of spines initiating a little before half of its length and not reaching apex, and not reaching level of femur where some apical spines of internal margin begin, internal margin only visible in this anterior portion; spines of moderate size, similar to some spines of protibiae. Metatrochanter modified like a small hook that does not exceed 1 / 4 of length of metafemur, hook curved only near apex (Fig. 13 b); metafemur without curvature in area of overlap with hook; metatibia straight. Tarsomeres slender, pooly flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed; depressed adjacent area with wide-superficial punctures moderately dense, which are missing or only sparse on remaining surface of these tergites, as well as following tergites, which have fine, sparse punctures. Visible sternites 1 – 4 with wide-superficial punctures in anterior half, and with fine, sparse punctures on remaining surface, as well as on remaining sternites. Male pregenital sternite weakly emarginate at posterior margin (Fig. 15 – l). Genital sternite moderately large (2.87 times longer than wide), moderately asymmetrical, anterior portion occupying 33 % and posterior portion 67 % of its length; apical emargination deep (Fig. 18 – o). Abdominal styli slender. Aedeagus: length 1.3 mm; cone-shaped, apex pointed; sides becoming regularly wider from apex to base; basal half notably wider than apical half; internal sac visible (Fig. 22 f). Variability. In measurements and ratios, the following variation was observed: total body length in males 10.5 mm (range 9.9 – 11.2 mm), in females 9.8 mm (range 8.5 – 10.5 mm); ratio length / width of head in males 0.77 (range 0.65 – 0.85), in females 0.88 (range 0.86 – 0.90); ratio mandibular length / cephalic length in males 1.25 (range 1.00 – 1.43), in females 0.86 (range 0.81 – 0.92); ratio cephalic width / pronotal width in males 1.23 (range 1.11 – 1.40), in females 1.06 (range 1.01 – 1.08); ratio length / width of pronotum in males 1.12 (range 1.03 – 1.20), in females 1.17 (range 1.12 – 1.21); ratio anterior width / posterior width of pronotum in males 1.05 (range 1.05 – 1.08), in females 1 (without variation). Apical antennomere, some times also subapical antennomere, lighter than the preceding ones. Most specimens have five punctures in each dorsal row of pronotum, with a variation of 5: 6, 6: 5 or as in the holotype. The anterior half of the mesoventrite may be reddish as on its posterior half or darker (brown). Taxonomic comments. Due to its color pattern, size and modification of the male metatrochanters, this species has been confused with B. trochanterinus in publications reporting the presence of B. trochanterinus in Mexico. The analysis of the holotype of this latter species has made it possible to distinguish them in a simple way because B. trochanterinus has abdominal styli that are very wide apically, while they are slender and elongate in B. tenuistylus, in addition to the differences in the shape of the genital sternite and the aedeagus of both species. Furthermore, B. tenuistylus resembles B. metafemoralis and in the taxonomic comments of this latter species it has been indicated how to distinguish them.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977037F2E81AFA3A7FAEBF8CD.taxon	etymology	Etymology. The name of this species is a combination of the words “ tenuis ” and “ stylus ”, in order to highlight the slender styli of this species that easily separate it from B. trochanterinus.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977037F2E81AFA3A7FAEBF8CD.taxon	materials_examined	Type material (18 males, 17 females): Holotype (male, CC-UAEH): “ México, Morelos, Tlayacapan, San José de los Laureles, camino a Amatlán, N 18 ° 58´5 ”, W 99 ° 00´5 ”, localidad 1, bosque de pino-encino, 1874 m, NTP- 80 (calamar), 1 a 30 - VIII- 1995, J. Márquez col. ” Paratypes: Mexico: Morelos: “ Tlayacapan, San José de los Laureles, NTP- 80, localidad 1, bosque de pino-encino, X- 1995, K. Villavicencio y J. Márquez cols. ” (6, CC-UAEH). Same data, except: “ Octubre- 1995 ” (4, MAAS). Same data, except: “ localidad 3, bosque mesófilo de montaña perturbado ” (3, MAAS). “ Tlayacapan, selva baja caducifolia, zona 4, NTP- 80, VI- 1996, J. Márquez y K. Villavicencio cols. ” (1, MAAS). “ Tlayacapan, San José de los Laureles, camino a Amatlan, N 18 ° 58 ’ 7 ”, W 99 ° 01 ’ 15 ”, 1783 m, bosque mesófilo de montaña, NTP- 80 (calamar), Julio- 1995, J. Márquez col. ” (2, MAAS). Same data, except: “ bosque de pino y pino-encino, agosto- 1995 ” (9, MAAS). Same data, except: “ bosque mesófilo de montaña, septiembre- 1995 ” (3, MAAS). Same data, except: “ bosque de pino-encino, octubre- 1995 ” (3, MAAS). Same data, except: “ bosque de pino, diciembre- 1995 ” (1, MAAS). Same data, except: “ bosque mesófilo de montaña, junio- 1996 ” (2, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977027F2C81AFA153FB4AFD61.taxon	description	Figs. 4 b, 11 d, 12 g, 14 b, 15 c, 19 a, 22 g, 29 b Total body length 11.6 mm. Black on head, antennae, mandibles (except apex and internal margins), pronotum, scutellum, posterior half of prosternum, sixth visible abdominal segment (except anterior border) and abdominal styli. Reddish on elytra, legs, sterna (except posterior half of prosternum and anterior half of mesoventrite), visible abdominal segments 1 – 5 and anterior border of sixth. Brown at apex and internal margins of mandibles, maxillary and labial palpi, anterior half of mesoventrite and genital segment. Head: transverse, ratio length / width 0.69. Dorsal surface with sulcate longitudinal midline visible from anterior margin to almost posterior margin of head, but less notable in posterior half; front clearly foveate between antennal insertions. Eyes slightly longer than 0.5 times the cephalic lateral length, not protruding laterally. Antennomeres 4 – 5 elongate, 6 – 7 as long as wide, 8 – 10 transverse. Mandibles 1.58 times longer than head; each with two well separated teeth (basal and middle); mandibular channel well developed, with external and internal margins moderately separated at base, internal margin carinate, extending forward to level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Head 1.3 times wider than pronotum. Thorax: each dorsal row of pronotum with five punctures; pronotum almost as long as wide (ratio 1.06) and almost as wide at anterior corners as at posterior corners (ratio 1.06). Scutellum with punctures denser than on elytra, latter with sparse punctation, with fine, pale setae. Prosternum with an elevated area next to anterior margin and a transverse line near the place where black color initiates. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly U-shaped, reaching close to margin of intercoxal process, but not touching it (Fig. 11 d). Profemur with external row of spines initiating near basal third and reaching the apex or very close to it, the most apical spines are placed at same level as spines of internal apex that are less numerous and shorter; external spines increasing in size from base to apex, where being conspicuous (Fig. 12 g). Metatrochanter modified like a hook that is as long as or longer than 1 / 2 length of metafemur, hook elongate, slender, with apex strongly curved and acute; metafemur with internal margin curved at level of overlap with hook; metatibia clearly curved at internal margin near basal third. Tarsomeres moderately flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed, adjacent zone slightly depressed and narrow (Fig. 14 b); tergite one with sparse, wide-superficial punctures in depression, becoming denser toward remaining surface; depression on visible tergites 2 – 3 with wide-superficial punctures denser than on remaining surface; all tergites also with fine punctures that are denser on last three visible tergites. All sternites (Fig. 14 b) with wide-superficial punctures denser than on tergites, but on sternites 5 – 6 less dense than on remaining sternites, also all sternites with fine punctures as on tergites. Male pregenital sternite without emargination at posterior margin (Fig. 15 c). Genital sternite short (2.31 times longer than wide), moderately asymmetrical, anterior portion occupying 40 % and posterior portion 60 % of its length; apical sinuation deep (Fig. 19 a). Abdominal styli very slender. Aedeagus: length 1.8 mm; oval-elongate shape, apex wide and slightly convex; sides with slight constriction before apex, widened toward base; basal half moderately wider than apical half, most notable in lateral view; paramere with irregular anterior margin (or a little jagged); internal sac visible (Fig. 22 g). Variability. Total body length in males 10.8 mm (range 9.9 – 12.0 mm), in females 9.8 mm (range 8.8 – 10.6 mm); ratio length / width of head in males 0.69 (range 0.67 – 0.74), in females 0.84 (range 0.82 – 0.87); ratio mandibular length / cephalic length in males 1.56 (range 1.33 – 1.70), in females 0.90 (range 0.82 – 0.96); ratio cephalic width / pronotal width in males 1.30 (range 1.21 – 1.36), in females 1.08 (range 1.00 – 1.15); ratio length / width of pronotum in males 1.06 (range 1.02 – 1.10), in females 1.14 (range 1.10 – 1.18); ratio anterior width / posterior width of pronotum in males 1.1 (range 1.07 – 1.18), in females 1.03 (range 1.00 – 1.04). Sulcate longitudinal midline of head may be less visible than in the holotype. In some specimens the entire prosternum is black. Posterior margin of male pregenital sternite can be weakly emarginate or without emargination, with the latter state being the most frequent. Taxonomic comments. This species is very similar to B. apiciventris and B. rufisternus, both in the color pattern as well as in the total length and other characters. In the description of B. apiciventris the main differences with this species are pointed out. Belonuchus tepoztecus is distinguished from B. rufisternus by having the anterior half of the mesoventrite black (or at least dark) and the posterior half reddish, five punctures in each dorsal row of pronotum, male pregenital sternite with emarginate posterior margin and different male genital sternite and aedeagus. Belonuchus rufisternus has the entire mesoventrite reddish, six punctures in each dorsal row of pronotum, male pregenital sternite moderately emarginate in posterior margin, and a different male genital sternite and aedeagus.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977027F2C81AFA153FB4AFD61.taxon	etymology	Etymology. The name of this species is derived from the geographical place of origin of the specimens, which is known as “ Sierra del Tepozteco ” in the state of Morelos.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977027F2C81AFA153FB4AFD61.taxon	materials_examined	Type material (63 males): Holotype (male, CC-UAEH): “ México: Morelos, Tlayacapan, San José de los Laureles, camino a Amatlán, bosque mesófilo de montaña, 1783 m, N 18 ° 58.7 ’, W 99 ° 01 ’, NTP- 80 (calamar), 1 a 30 - VII- 1995, J. Márquez col. ”. Paratypes (all specimen males): same data as holotype (16, CC-UAEH). Same data, except: “ 1 a 30 - VIII- 1996 ” (6, MAAS). Same data, except: “ 1 a 30 - IX- 1995 ” (5, MAAS). Mexico: Morelos: “ Tlayacapan, camino a Santa Catarina, N 18 ° 57´13 ”, W 99 ° 00´15 ”, 1550 m, Loc- 4, selva tropical caducifolia, 1 - 30 - VII- 1995, K. Villavicencio y J. Márquez cols. ” (3, MAAS). Same data, except: “ 1 a 30 - VIII- 1995 ” (1, MAAS). Same data, except: “ 1 a 30 - IX- 1995 ” (10, MAAS). Same data, except: “ 1 a 30 - X- 1995 ” (10, MAAS). Same data, except: “ 1 a 30 - XI- 1995 ” (2, MAAS). Same data, except: “ 1 a 30 - XII- 1995 ” (2, CC-UAEH). “ Tlayacapan, San José de los Laureles, Loc- 1, N 18 ° 58 ’ 33 ”, W 99 ° 00 ’ 47 ”, 2000 m, bosque de pino-encino, NTP- 80 (calamar, 1 - 30 - IX- 1995, J. Márquez col. ” (1, MAAS). Same data, except: “ 1 a 30 - XI- 1995 ” (1, MAAS). “ Tlayacapan, San José de los Laureles, bosque mesófilo de montaña, Loc. 3, 1803 m, NTP- 80 (pulpo), 28 - X a 19 - XI- 1989, G. Quiroz y J. L. Navarrete cols. ” (1, MAAS). Same data, except: Loc. 5, 1751 m, 21 - VII a 24 - VIII- 1991 ” (1, MAAS). Same data, except: “ bosque de pino-encino, Loc. 1, 1830 m, 8 a 29 - IX- 1990 ” (1, MAAS). Same data, except: “ 3 a 30 - VI- 1990 ” (1, MAAS). “ Ocuituco, Jumiltepec, trampa de fruta, 22 - VI- 1998, A. C. Deloya col. ” (1, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977007F3381AFA4EAFB79FB0D.taxon	description	Figs. 4 c, 13 a, 14 g, 16 i, 19 b, 22 h, 28 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977007F3381AFA4EAFB79FB0D.taxon	description	Head: transverse (ratio 0.76, range 0.68 – 0.82). Dorsal surface with sulcate longitudinal midline visible only in anterior half of head; front weakly foveate near anterior margin. Eyes slightly more than 0.5 times the cephalic lateral length, not protruding laterally. Antennomeres 4 – 6 elongate, 7 – 10 as long as wide. Mandibles longer than head (ratio 1.25, range 1.08 – 1.57); each with two well separated teeth (basal and middle), mandibular channel moderately developed, external margin widely separated from internal margin at their base, internal margin carinate, extending beyond level of middle tooth. Apical palpomere of maxillary palpi slightly longer than preapical palpomere; apical palpomere of labial palpi nearly 1.25 times longer than preapical palpomere. Head wider than pronotum (ratio 1.16, range 1.13 – 1.20). Neck in ventral view with microsculpture a little coarser than on ventral surface of head. Thorax: pronotum with five punctures in left and six punctures in right dorsal row, or five punctures in each row; pronotum slightly longer than wide (ratio 1.11, range 1.05 – 1.15) and almost as wide at anterior corners than at posterior corners (ratio 1.02, range 1.00 – 1.06). Scutellum with punctures denser than on elytra, latter with sparse punctation, with pale, fine setae. Anterior half of prosternum reddish and posterior half black, weakly elevated before anterior margin. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge broadly U-shaped, not meeting margin of intercoxal process laterally. Profemur with external row of spines initiating near basal third and not reaching apex, spines small, shorter than spines placed near apex of internal margin. Metatrochanter modified like a hook that is moderately longer and distinctly curved and acute at apex, at most 1 / 3 as long as length of metafemur (Fig. 13 a); metafemur moderately curved at level of overlap with hook; metatibia clearly curved in apical third. Tarsomeres flattened dorsally. Abdomen: first visible tergite with posterior basal transverse carina straight and well developed; visible tergites 2 – 3 with posterior basal transverse carina not completely developed, visible at center and becoming irregular toward sides until it fades; adjacent depressed area rather shallow and with wide-superficial punctures denser than on remainder of tergites, where punctures being fine and moderately dense, with short and long combined setae. Sternites with wide-superficial punctures notably denser than on tergites, combined with fine punctures. Male pregenital sternite with distinct emargination at posterior margin (Fig. 16 i). Male genital sternite moderately elongate (2.75 times longer than wide), slightly asymmetrical, anterior portion occupying 42 % and posterior portion 58 % of its length; apical emargination deep (Fig. 19 b). Abdominal styli very wide and flattened at apex, wider than width of metatibia, ventrally with very dense dark setae (Fig. 14 g). Aedeagus: length 1.8 mm; cone-shaped, apex moderately acute; sides becoming regularly wider toward base; basal half notably wider than apical half; internal sac visible (Fig. 22 h). Variability. In addition to the variation indicated in the measurements and ratios of the description, and in the number of punctures in dorsal rows of pronotum, the mandibular channel is better developed in the largest specimen, the prosternum may be almost black, anterior femur of males with the row of spines developed over almost the entire length of the external margin, with a space before the apicalmost spines as if one or two of them were missing, the male metatrochanter modified like a hook may be as long as 0.33 to 0.50 times the length of the metafemur, and the metafemur may vary in curvature at the level of overlap with the hook. Taxonomic comments. As indicated in the taxonomic comments of B. tenuistylus, both species have been confused in the past because they are somewhat similar, although they can be separated by means of the widened abdominal styli in males of B. trochanterinus. The recent review of two male specimens from Los Chimalapas, Oaxaca, have allowed the first correct record of B. trochanterinus in Mexico. In taxonomic comments of other species with which B. trochanterinus can be confused, characters that help distinguish them have been included. The redescription of this species is based on three male specimens that do not belong to the type series but were compared with it. The type specimens were studied at the beginning of the study (more than five years ago), when there was uncertainty about including descriptions and specific characters. The types were returned to the NHM, and at the time of preparing the descriptions with comparable information for each species, they were no longer available. Lectotype of this species is designated here by taking into account Article 74.7 of the ICZN and its recommendations for establishing as accurately as possible the correct identity of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977007F3381AFA4EAFB79FB0D.taxon	materials_examined	Type material examined (four males, three females): Lectotype (male, NHM): “ Philonthus trochanterinus Type D. S. Capetillo, Guat. Champion (on the plaque with the specimen) / Sp. figured / B. C. A. Col. I. 2. Philonthus trochanterinus Sharp / Syntype / Lectotype Philonthus trochanterinus Sharp, 1885; Márquez & Asiain des. 2022 ”. Paralectotypes: “ Philonthus trochanterinus Type D. S. Capetillo, Guat. Champion (on the plaque with the specimen) / B. C. A. Col. I. 2. Philonthus trochanterinus Sharp / Syntype ” (m 2, f 1, NHM). “ Capetillo, Guatemala, Champion / B. C. A. Col. I. 2. Philonthus trochanterinus Sharp / Syntype ” (f 2, NHM). “ P. trochanterinus D. S. Capetillo (in the plaque with the specimen) / Capetillo, Guatemala, Champion / B. C. A. Col. I. 2. Philonthus trochanterinus Sharp / Syntype ” (m 1, NHM). Additional material examined (three males): Mexico: Oaxaca: “ San Miguel Chimalapa, San Antonio, El Retén, El Gringo, N 16.6836 °, W 94.2623 °, 1600 m, NTP- 80, VI-VII- 2013, E. Mora y L. Delgado cols. ” (m 1, IEXA). Same data, except “ N 16.6787 °, W 94.2629 °, bosque mesófilo, coprotrampa, 22 - VII- 2017, E. Mora col. ” (m 1, IEXA). Guatemala: Jutiapa: “ Jerez, Volcán Chingo, N 14.11522 °, W 89.73026 °, 1610 m, bosque de encino-nuboso, en hojarasca cernida, 24 - VIII- 2014, M. Barrios col. ” (m 1, CC-UAEH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771F7F3181AFA306FA03FA9C.taxon	description	Figs. 4 d, 13 c, 17 n, 19 c, 22 i, 26 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771F7F3181AFA306FA03FA9C.taxon	description	Head: subquadrate; slightly transverse (ratio 0.81). Dorsal surface with moderate microsculpture like wavy lines; sulcate longitudinal midline visible in anterior half of head reaching level of eyes; front weakly foveate between antennal insertions and slightly posteriad. Eyes slightly more than 0.5 times the cephalic lateral length, somewhat protruding laterally. First antennomere slightly longer than 2 – 3 combined, 4 – 6 elongate, 7 as long as wide, 8 – 10 transverse. Mandibles 1.11 times longer than head; each with two small, well separated teeth (basal and middle); base of mandibles with conspicuous microsculpture like wavy lines; mandibular channel with external margin not carinate and internal margin carinate at base, extending like impressed line slightly forward of level of middle tooth. Apical palpomere of maxillary palpi 1.3 times longer than preapical palpomere. Apical palpomere of labial palpi 1.4 times longer than preapical palpomere. Head 1.11 times wider than pronotum. Ventral surface with fine, very sparse punctures. Thorax: pronotum with left dorsal row formed by five punctures and right dorsal row by six punctures; fore- most puncture in each row looks somewhat separated from anterior margin (at least by one puncture diameter); ratio length / width of pronotum 1.17; as wide at anterior corners than as posterior corners. Scutellum with punctures sparse; elytra with punctures moderately dense. Prosternum elevated near anterior margin, but without constriction separating this area from remaining surface. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge not very distinct, broadly U-shaped, reaching close to margin of intercoxal process, but not touching it. Profemur with external row of spines as widely separated from base as from apex, formed by eight to nine spines slightly increasing in size toward apex, but smaller than spines of anterior tibiae; internal margin with four to five apical small spines. Metatrochanter with apex straight and pointed, not forming a hook, as long as 1 / 4 of length of metafemur, which is clearly curved at internal margin for about 1 / 2 of its length (Fig. 13 c). Metatibia straight. Tarsomeres slender and flattened dorsally. Abdomen: visible tergites 1 – 3 with posterior basal transverse carina not completely straight, faintly visible on tergite 3; adjacent area almost flat on tergite 1 and slightly depressed on tergites 2 – 3; entire surface of tergite 1 with sparse, wide-superficial punctures combined with fine punctures; tergites 2 – 4 with wide-superficial punctures combined with fine punctures in anterior half, posterior half only with sparse, fine punctures; tergites 5 – 6 only with sparse, fine punctures. Sternites with pattern of punctures as on tergites. Male pregenital sternite with posterior margin slightly carinate, acute at center and straight at sides (Fig. 17 n). Male genital sternite very long (3.33 times longer than wide), slightly symmetrical, anterior portion occupying 50 % and posterior portion 50 % of its length; apical emargination deep (Fig. 19 c). Abdominal styli slender at apex. Aedeagus: length 1.5 mm; elongate shape, with apex moderately acute; apical half moderately narrower than basal half; internal sac visible, very characteristic (Fig. 22 i). Variability. Only one other female specimen of the type series is available, which has a total length of 13.1 mm (bigger than male); ratio length / width of head 0.82; mandibular length / cephalic length 1.07; cephalic width / pronotal width 1.06; length / width of pronotum 1.19; anterior width / posterior width of pronotum 1.0. The number of punctures in each dorsal row of pronotum is six (also the first one is somewhat separated from anterior margin). Taxonomic comments. We first believe it is necessary to explain why we have included B. zunilensis in the trochanterinus group and not B. aenigmaticus, since the males of both species have a metatrochanter acute apically. We studied only one male specimen of B. zunilensis, the lectotype. We assume that the small spine of the metatrochanter of this specimen, not forming a hook, corresponds to a small size specimen, and we suppose that in large specimens the metatrochanter can be a hook, as has been noticed in other species of this group, as B. apiciventris. Also, the metafemur is clearly curved at the internal margin for about 1 / 2 of its length, this suggests the possibility that the metatrochanter can be a hook in this species because this curvature in the metafemur may be a modification for not hindering the hook or to accommodate the hook, as we observed in several species of this group. However, these asseverations can be tested until more male specimens of this species can be studied. For now, we decided to place this species as part of the trochanterinus group. On the other hand, we analyzed 10 male specimens of B. aenigmaticus. In all males, the apex of the metatrochanter ends in a small spine and the metafemur is not curved. We suppose the variability in body size of males of B. aenigmaticus is represented by the 10 studied specimens (8.1 – 9.6 mm), as well as the poor or not variability of the metatrochanter and metafemur. So, we think it is less possible that this species can be part of the trochanterinus group, but it is necessary to study more specimens, and also it is the reason for the name of this species	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771F7F3181AFA306FA03FA9C.taxon	materials_examined	Type material examined (one male, one female): Lectotype (male, NHM): “ Philonthus zunilensis Type D. S. Cerro Zunil 4 - 5000 ft / Type / B. C. A. Col. I. 2 Philonthus zunilensis, Sharp / Cerro Zunil, Guatemala. Champion / Sharp Coll. 1905 - 313 / Lectotype Philonthus zunilensis Sharp, 1885, Márquez & Asiain des. 2022 ”. Paralectotype: “ Philonthus zunilensis D. S. Cerro Zunil, Guatemala, 4 - 5000 ft. Champion (on the plaque with the lectotype) / Cerro Zunil Guatemala, Champion / B. C. A. Col. I. 2 Philonthus zunilensis, Sharp / Sharp Coll. 1905 - 313 ” (f 1, NHM). Group 2: rufipennis Included species: B. bidens Sharp, 1885, B. erichsoni Bernhauer, 1917, B. jalappensis Bernhauer, 1917, B. mixtecus sp. nov., B. pollens Sharp, 1885, and B. rufipennis (Fabricius, 1801).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771F7F3181AFA306FA03FA9C.taxon	diagnosis	Diagnosis of the rufipennis group: head without temporal carina; male mandibles not expanded at base (Fig. 10 e); mandibular length very variable; number of punctures in each dorsal row of pronotum variable; elytra reddish, abdomen bicolored (reddish and black); both sexes with unmodified posterior trochanters; males with two rows of spines on the inside of the posterior femora (except B. jalappensis that has spines in both sexes, although they are small) (Figs. 13 d – f); tarsomeres somewhat flattened dorsally; aedeagus with reduced paramere (Figs. 23 a – f).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771D7F3781AFA3F7FAC7FC41.taxon	description	Figs. 4 e, f, 10 e, 11 e, 12 h, 15 m, 19 d, 23 a, 30 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771D7F3781AFA3F7FAC7FC41.taxon	description	Head: transverse, ratio length / width in males 0.71 (range 0.50 – 0.82), in females 0.79 (range 0.77 – 0.82); with posterior corners and postero-dorsal part somewhat convex. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front foveate near anterior margin, in males this foveate area is placed between the two rather short cephalic projections at internal side of each antennal insertion (Fig. 10 e). Eyes large, slightly more than 0.5 times the cephalic lateral length, not protruding laterally. Antennomere 4 elongate, 5 as long as wide, 6 – 10 transverse. Mandibles longer than head in males (ratio 1.26, range 1.10 – 1.48) and shorter than head in females (ratio 0.90, range 0.84 – 0.97); each with two small, moderately separated teeth (basal and middle); mandibular channel slightly developed, with external margin slightly separated from internal margin, internal margin like impressed line, markedly extending anteriad of middle tooth. Apical palpomere of maxillary and labial palpi 1.25 to 1.48 times longer than preapical palpomere. Head slightly wider than pronotum in males (ratio 1.14, range 1.06 – 1.18), and almost equally wide in females (ratio 1.03, range 0.95 – 1.07). Thorax: each dorsal row of pronotum with five punctures; pronotum almost as long as wide (ratio in males 1.04, range 1.00 – 1.14, in females 1.07, range 1.00 – 1.11) and almost as wide at anterior corners as at posterior corners (ratio in males 1.08, range 1.06 – 1.12, in females 1.03, range 1.03 – 1.05). Scutellum and elytra with fine punctures and setae moderately dense. Prosternum with area near to anterior margin slightly elevated and delimitated backward by a faintly impressed transverse line. Intercoxal process of mesoventrite shield-shaped, rather broad and with obtuse-angled tip; transverse discal ridge almost parallel to margin of intercoxal process, not meeting margin of process laterally (Fig. 11 e). Profemur of males with external and internal margins well differentiated and each with row of spines; external margin curved downward near apex, distinctly narrowed and forming kind of notch where protibia would fit; external row of spines initiating slightly before base and reaching initial part of curvature, with fewer spines than on internal margin; spines on internal margin initiating from base, where there are additional non-aligned spines, but row of spines continuing until apex (Fig. 12 h). Metafemur of males with two rows of large and dark spines on ventral surface, internal row well aligned from base until apical third, external row not clearly aligned because of additional, non-aligned spines at base. Tarsomeres dorsally flattened. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent area slightly depressed and narrow, with moderately dense wide-superficial punctures that are decreasing toward posterior margin, combined with fine, moderately dense punctures; fourth visible tergite with punctures similar to that of previous tergites, visible tergites 5 – 6 only with fine, moderately dense punctures. Visible sternites 1 – 4 with similar punctures as on tergites 1 – 4, but with denser wide-superficial punctures; sternites 5 – 6 only with fine punctures. Male pregenital sternite slightly emarginate at posterior margin, with long setae at sides and shorter, finer setae at center (Fig. 15 m). Male genital sternite short (2.26 times longer than wide), very asymmetrical, anterior portion occupying 29 % and posterior portion 71 % of its length, apical emargination deep (Fig. 19 d). Abdominal styli pale, but with apical third darker, slender, with lateral margin slightly curved. Aedeagus: length 1.65 mm; rounded shape in basal half and elongate in apical half; apex wide at sides, with a minute median projection; basal half notably wider than apical half; internal sac visible, with characteristic shape (Fig. 23 a). Variability. In addition to the variation in the measurements and ratios indicated in the description, it was observed, in both males and small females, that antennomeres 5 – 10 may be transverse instead of as long as wide. In some specimens the punctures of scutellum are denser than on elytra. Females do not have the apex of the anterior tibiae widened and curved to form a notch. Taxonomic comments. Belonuchus bidens is differs from the rest of species of rufipennis group by its unique coloration pattern, in which the elytra, scutellum, legs and last two visible abdominal segments (fifth only the posterior half) are reddish and the rest of the body is black; additionally, the males have two projections in the form of short horns on the frons, next to the antennal insertions. The aedeagus and genital sternite are also rather distinctive in this species. The syntypes of this species were not studied, but we analyzed some photos of these specimens (Fig. 4 e; NHM, shared by M. Chani Posse), which together with the information of the original description (Sharp 1885) allowed us to identify this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771D7F3781AFA3F7FAC7FC41.taxon	materials_examined	Material examined (34 males, 21 females): Mexico: Hidalgo: “ Chapulhuacán Arroyo Blanco, bosque tropical subcaducifolio, 239 m, N 21 ° 09.286 ’, W 99 ° 00.331 ’, NTP- 80 # 2 (calamar), 30 - III a 06 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 3 (calamar) ” (3, CC-UAEH). “ Huautla, 2 km NW de Tohuaco Amatzintla, N 21 ° 07´23 ”, W 98 ° 16´51 ”, bosque tropical subcaducifolio, trampa cebada con champiñones, 17 a 28 - IV- 2015, R. Ramírez y J. Márquez cols. ” (2, CC-UAEH). “ Huehuetla, Rio Blanco, 588 m, UTM (WG- 384), 14 94809, NTP- 80 (calamar), 1 a 30 - V- 2010, C. Berriozábal col. ” (22, CC- UAEH). “ La Misión, Lomas del Pericón, bosque mesófilo de montaña, 1377 m, N 21 ° 6.0 ’ 46.0 ”, W 99 ° 6.0 ’ 15.6 ”, trampa de intercepción de vuelo # 1, 26 - VIII a 9 - IX- 2011, J. Márquez col. ” (1, CC-UAEH). Puebla: “ Tlacuilotepec, cerca del río San Marcos, N 20 ° 19 ’ 22.5 ”, W 98 ° 02 ’ 35.4 ”, bosque tropical subcaducifolio, trampa con fruta, 13 a 25 - X- 2018, J. Márquez y J. D. Silva cols. ” (m 1, CC-UAEH). Same data, except: “ NTP- 80, 17 - VII a 19 - VIII- 2018, J. D. Silva-Hurtado col. ” (3, CC-UAEH). “ Xicotepec de Juárez, Cañada de Patla, bosque mesófilo de montaña perturbado, 11 - IX- 1994, en tronco caído, J. Márquez col. ” (1, MAAS). “ Xicotepec de Juárez, Hidroeléctrica Patla, bosque mesófilo de montaña perturbado, en necrotrampa temporal (calamar), 27 - III- 1998, O. Pérez col. ” (2, MAAS). “ Xicotepec de Juárez, Hidroeléctrica Plata, selva mediana, 457 m, en plantas, 5 - X- 2002, J. Asiain y J. Márquez cols. ” (1, MAAS). Same data, except: “ 487 m, en inflorescencia de plátano, 6 - III- 2002. ” (1, MAAS). San Luis Potosí: “ Xilitla, Las Pozas de James, N 21 ° 23 ’ 55.7 ”, W 98 ° 56 ’ 6.7 ”, bosque tropical subperenifolio, 585 m, bajo rocas a orilla del río, 16 - VII- 2007, J. Asiain y J. Márquez cols. ” (1, CC-UAEH). Veracruz: “ Catemaco, Estación Biológica “ Los Tuxtlas ”, en frutos podridos, 20 al 24 - II- 1994, J. Márquez col. ” (1, MAAS). Same data, except: “ caminando ” (1, MAAS). “ Catemaco, Pipiapan, N 18 ° 27´, W 95 ° 03´, feb-march, 1991, M. A. Morón, ex carrion trap ” (1, IEXA). “ Córdoba, San Rafael Calería, Ojo de Agua, selva mediana subcaducifolia, 1127 m, en lima podrida, Q. Santiago y J. Márquez cols. ” (1, MAAS). “ Córdoba, San Rafael Calería, Ojo de Agua, selva mediana subcaducifolia, 1127 m, en lima podrida, Q. Santiago y J. Márquez cols. ” (1, MAAS). “ Córdoba, San Rafael Calería, Ojo de Agua, N 18 ° 57 ’ 15 ”, W 96 °, 56 ’ 24 ”, selva mediana subcaducifolia, 1127 m, NTP- 80 (calamar), 20 - III a 17 - IV- 1999, Q. J. Santiago, J. Márquez y J. Asiain cols. ” (2, MAAS). “ Córdoba, Cuauhtémoc, 940 m, 24 - VI- 1992, NTP- 80, R. Hernández col. ” (1, IEXA). “ Ilamatlán, Xococapa, bosque tropical subperenifolio, 388 m, N 20 ° 48 ’ 24.9 ”, W 98 ° 20 ’ 24.7 ”, NTP- 80 (calamar) # 3, 13 - VIII a 10 - IV- 2006, F. Ramírez col. ” (1, CC-UAEH). Same data, except: “ 397 m, N 20 ° 48 ’ 24.0 ”, W 98 ° 20 ’ 24.6 ”, NTP- 80 # 4, 05 - III a 01 - IV- 2006. ” (1, CC-UAEH). Same data, except: “ 362 m, N 20 ° 48 ’ 20.3 ”, W 98 ° 20 ’ 31.5 ”, NTP- 80 # 2 ” (1, CC-UAEH). “ Totutla, Mata Oscura, Rancho Zacuapan, N 19 ° 12 ’ 23 ”, W 96 ° 50 ’ 32 ”, 869 m, naranja podrida, 18 - V- 1999, J. Asiain, Q. Santiago y J. Márquez cols. ” (1, MAAS). Same data, except: “ 24 - II- 1994 ” (1, MAAS). Same data, except: “ en mandarina podrida, 18 - V- 1999 ” (2, MAAS). “ Xico, km 1.2 camino a cascadas de Texolo, cultivo de café, en plátano en descomposición, 12 - XI- 1997, Q. Santiago col. ” (1, QJSJ).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771B7F3581AFA5CAFA94FE81.taxon	description	Figs. 4 g, 17 m, 19 e, 23 b, 27 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771B7F3581AFA5CAFA94FE81.taxon	description	Head: transverse, ratio length / width in males 0.79 (range 0.71 – 0.86), in females 0.86 (range 0.80 – 0.89); convex at posterior corners. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front rounded foveate slightly backward of level of antennal insertions. Eyes slightly shorter than 0.5 times the cephalic lateral length, not protruding at sides. Antennomeres 2 – 3 almost equal in length, 4 – 6 elongate, 7 as long as wide, 8 – 10 transverse. Males with mandibles 1.23 times longer than head (range 1.03 – 1.50), in females almost as long as head (0.975 times, range 0.92 – 1.03); each with two small, moderately separated teeth (basal and middle); mandibular channel slightly developed, with external margin not carinate, internal margin like impressed line extending beyond level of middle tooth. Ventral surface lacking puncture at external anterior quarter, only with very fine and sparse punctures. Males with head 1.13 times wider than pronotum (range 1.03 – 1.22), in females 1.07 (range 1.03 – 1.12). Neck in ventral view with microsculpture a little coarser than on head. Thorax: each dorsal row of pronotum with six or seven punctures, less frequently five punctures; males with pronotum 1.14 times longer than wide (range 1.10 – 1.20), in females 1.2 (range 1.16 – 1.25); in both sexes almost as wide at anterior corners than at posterior corners (ratio in males 1.08, range 1.03 – 1.12, in females 1.06, range 1.03 – 1.07). Scutellum and elytra with fine punctures moderately dense. Prosternum slightly elevated behind posterior margin. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly Ushaped, not touching margin of intercoxal process laterally. Profemur of males somewhat widened toward anterior portion, but near apex is narrowed by means of a curvature, although not forming an apical notch as clear as in B. bidens; external row of spines well developed from base to before narrow part; internal row with very small spines that are increasing in size toward apex, where some of them are longer than spines of external side. Metafemur of males with two rows of spines not well aligned at base, where there are additional spines, but well aligned distad; reaching slightly more than 1 / 2 of length of posterior femur; spines of external side are longer and wider than spines of internal side, and comparatively bigger than spines of B. rufipennis. Metatibiae straight. Tarsomeres moderately flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed, fourth visible tergite with posterior basal transverse carina as indistinct line on sides and absent at center; adjacent area of first three visible tergites narrow and slightly depressed, with wide-superficial punctures moderately dense that disappear backwards; additionally, entire surface of each tergite with fine, sparse punctures; punctures on tergite four similar to that of anterior tergites, tergites 5 – 6 only with fine puctures. Sternites with density and type of punctures similar to that on tergites. Male pregenital sternite strongly emarginate at posterior margin, emargination U-shaped or V-shaped, as deep as 1 / 5 to 1 / 4 of total length of sternite (Fig. 17 m). Male genital sternite short (2.29 times longer than wide), moderately asymmetrical, anterior portion occupying 39 % and posterior portion 61 % of its length, apical emargination very deep (Fig. 19 e). Abdominal styli slender, with apex slightly rounded. Aedeagus: length 1.95 mm; oval-elongate shape, with apex slightly acute and narrowed apicad, with a circular line at base of median lobe; basal half moderately wider than apical half; internal sac conspicuous (Fig. 23 b). Variability. In addition to the variation in measurements and ratio included in the description, and variation due to sex and size of specimens, frequent variation was observed in the number of punctures in each dorsal row of pronotum: 5: 6, 6: 5, 7: 6, 6: 7; the punctures on scutellum may be slightly denser than on elytra; sixth visible abdominal segment may present an irregular border between black and reddish color, but the proportion is always close to basal 3 / 4 black and apical 1 / 4 reddish. Taxonomic comments. This species can be confused with B. mixtecus, B. pollens and B. rufipennis, due to its similar coloration pattern and the presence of two rows of spines on the male posterior femora. It is distinguished from B. pollens and B. rufipennis by having 6 – 7 punctures in at least one dorsal row of pronotum and abdomen with only the sixth visible segment black (with the anterior border reddish); while the two previous species have five punctures in each dorsal row of pronotum and part of the fifth visible abdominal segment and entire sixth black. With B. mixtecus it shares having six or seven punctures in at least one dorsal row of pronotum, male pregenital sternite deeply emarginate at posterior margin, and shape and size of genital sternite and aedeagus, although the latter two characters are quite similar but not identical in these species. They can be distinguished because B. erichsoni has the sixth visible abdominal segment black (with the anterior border reddish), metafemora of males not flattened in basal half of external surface, metatibiae of males straight, fourth visible abdominal tergite with posterior basal transverse carina as indistinct line laterally and absent medially, and because its aedeagus is of oval-elongate shape, with the median lobe evenly converging to apex. While in B. mixtecus, most of fifth and entire sixth visible abdominal segments are black, metafemora of males are somewhat widened and flattened in basal half of external surface, metatibiae of males are faintly curved at half length, fourth visible abdominal tergite does not have the posterior basal transverse carina, and its aedeagus is oval-shaped, more widened and with the median lobe parallel-sided for most of its length. The holotype was studied and compared with non-type specimens earlier, but was not available when the detailed descriptions of the species were made, so this redescription is based on non-type specimens.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789771B7F3581AFA5CAFA94FE81.taxon	materials_examined	Type material examined: Holotype (male, FMNH): “ Mexiko, Bang Haas / erichsoni Brh., Mexiko, Type, Det. Bernhauer / Bernh., Type unic / Chicago NHMus, M. Bernhauer Collection / Belonuchus erichsoni Bernhauer ”. Additional material examined (23 males, 23 females): Mexico: Estado de México: “ Otumba, Belem, N 19 ° 37´47 ”, W 98 ° 48´7 ”, en cultivo de nopales, trampa cebada con nopales fermentados, 20 - VIII a 4 - IX- 2017, A. Hernández y A. Rojas cols. ” (26, CC-UAEH). Hidalgo: “ Acatlán, Loma Larga, El Llano, cultivos, matorral xerófilo y encinos, 2097 m, N 20 ° 16 ’ 13 ”, W 98 ° 28 ’ 18 ”, NTP- 80 (calamar) 13 al 20 - VII- 2010, J. Márquez y J. Asiain cols. ” (2, CC- UAEH). “ Huasca de Ocampo, Sta. María Regla, a los rededores del rio, cultivos y Juniperus, en nopales podridos, 27 - VIII- 2014, J. Márquez col. ” (2, CC-UAEH). “ Santiago de Anaya, El Encinal, N 20 ° 26 ’ 56.0 ”, W 98 ° 55 ’ 20.5 ”, matorral xerófilo y encinos, trampa cebada con nopales fermentados, 22 a 29 - VII- 2018, F. M. Gómez e I. S. Hernández cols. ” (1, CC-UAEH). “ Zempoala, Sierra de Pitos, cerca de Mina San Juan Tepemazalco, bosque de encino, 2680 m, N 19 ° 54 ’, W 98 ° 43 ’, en nopales podridos, 10 - IX- 2002, J. Márquez col. ” (1, CC-UAEH). “ Zempoala, La Trinidad, matorral xerófilo, 2451 m, N 19 ° 57 ’ 75.9 ”, W 98 ° 43 ’ 58.7 ”, NTP- 80 (carne de cerdo), 4 al 18 - VIII- 2004, T 14, G. Pajas y J. Márquez cols. ” (2, CC-UAEH). Same data, except: “ 4 al 25 - VIII- 2004, T 9 ” (2, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Trancas, bosque de pino-encino, 2444 m, N 20 ° 48 ’ 12.22 ”, W 99 ° 14 ’ 41 ”, en nopal podrido, 18 - IX- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (2, CC-UAEH). Same data, except: “ coprotrampa, 12 - VII a 17 - VIII- 2007, J. Asiain, S. Sierra y J. Márquez cols. ” (2, CC-UAEH). Same data, except: “ NTP- 80, 22 - VII a 17 - VIII- 2007 ” (1, CC-UAEH). Same data, except: “ 17 - VIII a 19 - IX- 2007 ” (1, CC-UAEH). Same data, except: “ NTP- 80, 13 - X a 17 - XI- 2007 ” (1, CC-UAEH). Same data, except: “ nopal podrido, 18 - IX- 2007 ” (1, CC-UAEH). Querétaro: “ Ezequiel, Montes, Bernal, El Descanso, matorral xerófilo, 2100 m, 5 - III- 1999, en nopales podridos, S. Arenas y J. Márquez cols. ” (1, MAAS). Same data, except: “ 3 - III- 1999, J. Márquez col. ” (1, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977197F3481AFA78AFDBCFC08.taxon	description	Figs. 4 h, 11 f, 15 d, 19 f, 23 c, 30 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977197F3481AFA78AFDBCFC08.taxon	description	Head: shape subquadrate, in large specimens, head wider at posterior corners, which are convex; ratio length / width in males 0.88 (range 0.85 – 0.91), in females 0.86 (range 0.84 – 0.88). Dorsal surface with deep and conspicuous punctures, distributed as in majority of species; sulcate longitudinal midline visible for almost entire cephalic length, more distinctly on front and at center of head; front little to moderately foveate at level of antennal insertions. Eyes small, in small specimens slightly less than 0.5 times the cephalic lateral length, even smaller in large specimens, not protruding at sides. Antennomeres 4 – 10 transverse. Mandibles shorter than head in both sexes (ratio in males 0.77, range 0.68 – 0.82, in females 0.73, range 0.67 – 0.79); left mandible with two small middle teeth very close to each other, forming a small arc; right mandible with a middle tooth in dorsal position very close to a very small ventral tooth; both mandibles without basal tooth and with rough lines in their middle dorsal area; external channel moderately developed, external margin a little separated from internal margin, internal margin slightly carinate at base, extending forward like impressed line a little beyond level of middle teeth. Apical palpomere of maxillary and labial palpi slightly longer than preapical palpomere. Head in males 1.24 times wider than pronotum (range 1.15 – 1.32), in females 1.17 (range 1.04 – 1.26). Thorax: each dorsal row of pronotum with four punctures that do not extend beyond midlength, with second and third punctures closer to each other than to other punctures; pronotum almost as long as wide in both sexes (ratio in males 1.04, range 1.0 – 1.1, in females 1.06, range 1.03 – 1.10) and wider at anterior corners than at posterior corners (ratio in males 1.2, range 1.15 – 1.25, in females 1.2, range 1.17 – 1.26). Scutellum somewhat elongate, with fine punctures moderately dense, as it is on elytra. Anterior area of prosternum clearly elevated transversally. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge weakly to moderately visible, broadly V-shaped, not touching margin of intercoxal process laterally (Fig. 11 f). Profemur of males not notably widened apically as in B. bidens, external row with few short spines, not more than ten, separated from both base and apex; internal row with spines even smaller than spines in external row, toward the apex are transforming to wide setae and becoming spines again near apex. Metafemur of males with two rows of small spines on its ventral surface that initiate near base and end slightly before apex, each composed of less than ten spines. Tarsomeres robust, flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent area not depressed or weakly so, with sparse wide-superficial punctures, combined with more dense fine punctures, which also cover the main part of last two tergites. Tergites 4 – 5 with microsculpture like mesh covering anterior third; this microsculpture is not present on remaining surface of these tergites as well as on remaining tergites. Visible sternites 1 – 4 with wide-superficial punctures in anterior half slightly denser than on tergites, combined with finer punctures; with mesh-like microsculpture covering slightly more than on tergites 4 – 5. Male pregenital sternite not emarginate at posterior margin (Fig. 15 d). Male genital sternite moderately large (2.86 times longer than wide), very asymmetrical, anterior portion occupying 17 % and posterior portion 83 % of its length, apical emargination deep (Fig. 19 f). Abdominal styli slender. Aedeagus: length 1.25 mm; slender, cone-shaped; apex slightly rounded, sides gradually widening toward base in almost straight line; basal half moderately wider than apical half; internal sac not visible (Fig. 23 c). Variability. In addition to the measurements and ratios included in the description, there is variation in the color of femora and tibiae that can be dark or light brown, last antennomere lighter than previous ones, black and reddish color of third visible abdominal segment may vary from 1 / 2 to 2 / 3 black at base. Taxonomic comments. This species is easily distinguished from the rest of species in this group by having pronotum, elytra and first two (and part of third) visible abdominal segments reddish, in addition to its robust body shape, with mandibles shorter than head, male pregenital sternite not emarginate at posterior margin and the shape and size of the aedeagus (Fig. 23 c). The redescription of this species was made based on non-type specimens due to the same situation as in B. erichsoni. That is, the type specimens were studied, but were not available at the time of redescription. Lectotype of this species is designated here taking into account Article 74.7 of the ICZN (1999) and its recommendations, to establish more clearly the identity of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977197F3481AFA78AFDBCFC08.taxon	materials_examined	Type material examined (two males): Lectotype (male, FMNH): “ Jalapa, Mex, Dabbert / jalappensis, Bernh. Typus, Chicago NHMus, M. Bernhauer Collection / Lectotype Belonuchus jalappensis Bernhauer, 1917, Márquez & Asiain des. 2022 ”. Paralectotype: “ Mexico, Jalapa, coll. Schneider / jalappensis, Bernh. Cotypus / Chicago NH- Mus, M. Bernhauer Collection ” (m 1, FMNH). Additional material examined (10 males, eight females): Mexico: Hidalgo: “ Molango, Acuatitlán, bosque mesófilo de montaña, 1715 m, N 20 ° 45 ’ 38.4 ”, W 88 ° 42 ’ 50.7 ”, trampa de intercepción de vuelo # 3, 15 a 29 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). “ Tenango de Doria, El Potrero, bosque mesófilo de montaña, 2185 m, N 20 ° 18 ’ 49.5 ”, W 98 ° 13 ’ 48.3 ”, en tronco de descomposición, 18 - IV- 2009, M. Torres, M. Rivero, J. Sánchez, M. Vargas y J. Márquez cols. ” (8, CC-UAEH). Same data, except: “ 25 - IV- 2009, M. Torres, M. Rivero y J. Márquez cols. ” (5, CC-UAEH). “ Tenango de Doria, La Viejita, N 20 ° 19´37.5 ”, W 98 ° 16´7.3 ”, bosque mesófilo de montaña, 1500 m, trampa de intercepción de vuelo, 5 a 10 - V- 2013, N. Gutiérrez col. ” (m 1, CC-UAEH). Puebla: “ Zacapoaxtla, Ex-hacienda Apulco, cascada La Gloria, N 19 ° 54´12 ”, W 97 ° 37´00 ”, 1,508 m, dentro de cañada bosque mesófilo de montaña rodeado por pinos, trampa de intercepción de vuelo, 18 a 28 - V- 2021, familia Márquez-Asiain cols. ” (3, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977187F3B81AFA202FA82FA79.taxon	description	Figs. 5 a, 13 e, 17 o, 19 g, 23 d, 27 b Total body length 12.5 mm. Black on head, antennae, mouthparts, pronotum, scutellum, prosternum, anterior half of mesoventrite, from fifth visible abdominal segment (except 1 / 4 to 1 / 5 anterior) to genital segment and abdominal styli. Reddish on elytra, posterior half of mesoventrite, metaventrite, legs, visible abdominal segments 1 – 4 and anterior 1 / 4 to 1 / 5 of fifth. Head: transverse, ratio length / width 0.65, postero-dorsal area and posterior corners convex. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front foveate between antennal insertions. Eyes less than 0.5 times the cephalic lateral length, not protruding laterally. Antennomere 2 almost as long as 3, 4 – 6 elongate, 7 as long as wide, 8 – 10 transverse. Mandibles very long, 1.75 times longer than head; each with two very close teeth, basal tooth bigger than middle tooth; mandibular channel moderately developed, external margin slightly carinate, internal margin carinate, extending beyond level of middle tooth. Apical palpomere of maxillary and labial palpi almost as long as preapical palpomere. Head 1.23 times wider than pronotum. Thorax: left dorsal row with seven punctures and right dorsal row with six punctures; pronotum 1.12 times longer than wide and 1.13 times wider at anterior corners than at posterior corners. Scutellum with punctures slightly denser than on elytra, where it is moderately dense. Prosternum slightly elevated transversally before anterior margin. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly Ushaped, not meeting margin of intercoxal process laterally. Profemur slightly widened toward apex (less noticeable than in B. bidens); external margin with row of short, dark and dense spines that initiate near base and end at apex where margin is narrow; internal margin with row of spines even shorter (difficult to see), initiating further apicad than external row and reaching apex, where four to six spines are longer than previous spines; with a few spines at base of femur between both rows. Metafemur somewhat widened and flattened in basal half of external surface (Fig. 13 e); with two rows of spines not clearly aligned at base, where there are some additional spines, spines are best aligned more distally; spines extending close to 3 / 4 of length of femur; spines of external side stronger and longer than spines of internal side, and also longer than spines in B. rufipennis. Metatibiae weakly curved at midlength. Tarsomeres moderately flattened dorsally. Abdomen: first three visible abdominal tergites with posterior basal transverse carina well developed; adjacent area a little depressed and with sparse, wide-superficial punctures combined with fine punctures moderately dense; visible tergite 4 with punctures as on tergites 1 – 3; visible tergites 5 – 6 only with fine punctures. Visible sternites 1 – 4 with punctures as on tergites 1 – 3, but wide-superficial punctures slightly denser; sternites 5 – 6 only with fine punctures. Male pregenital sternite with deep, narrow U-shaped emargination at posterior margin, as deep as nearly 1 / 5 of length of sternite (Fig. 17 – o). Male genital sternite short (1.94 times longer than wide), moderately asymmetrical, anterior portion occupying 39 % and posterior portion 61 % of its length, apical emargination deep (Fig. 19 g). Abdominal styli large. Aedeagus: length 1.9 mm; oval shape; apex of median lobe narrow and rounded, median lobe parallel sided and narrow, compared to rest of aedeagus which is wider; apical half of aedeagus becoming narrow to base of median lobe, basal half of aedeagus with sides almost homogeneous in width; internal sac visible in anterior half (Fig. 23 d). Variability. Total body length in males 11.9 mm (range 10.7 – 12.7 mm), in females 13.0 (range 12.6 – 13.5); ratio length / width of head in males 0.75 (range 0.67 – 0.86), in females 0.87 (range 0.86 – 0.88); ratio mandibular length / cephalic length in males 1.35 (range 0.96 – 1.67), in females 1.0 (without variation); ratio cephalic width / pronotal width in males 1.18 (range 1.08 – 1.26), in females 1.05 (range 1.03 – 1.06); ratio length / width of pronotum in males 1.12 (range 1.10 – 1.16), in females 1.2 (range 1.18 – 1.22); ratio anterior width / posterior width of pronotum in males 1.12 (range 1.07 – 1.15), in females 1.08 (range 1.07 – 1.10). Dorsal rows of punctures on pronotum vary from 7: 7, 6: 6 to 6: 7; anterior half of prosternum may be reddish-brown; in small males, spines of posterior femora may be better aligned and, those at its base smaller than they are in large specimens; fifth visible abdominal segment may be black in posterior half and reddish in anterior half, or reddish until anterior 1 / 4. Taxonomic comments. Belonuchus mixtecus has a body coloration similar to B. pollens and B. rufipennis, and it is distinguished from both species by the dorsal rows of pronotum formed by six or seven punctures, the more robust body, the male pregenital sternite deeply emarginate at posterior margin and aedeagus large and oval. While in B. pollens and B. rufipennis there are five punctures in each dorsal row of pronotum, the body is less robust, male pregenital sternite is slightly to moderately emarginate at posterior margin, and their aedeagus is smaller and elongate. Belonuchus mixtecus can also be confused with B. erichsoni, and their differences have been indicated in the taxonomic comments of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977187F3B81AFA202FA82FA79.taxon	etymology	Etymology. The name of this species refers to the geographical place where it was collected, which is called the “ Mixteca Alta ” region of Oaxaca.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977187F3B81AFA202FA82FA79.taxon	materials_examined	Type material (five males, two females): Holotype (male, CC-UAEH): “ México: Oaxaca, San Mateo Peñasco, en jardín, 1788 m, N 17 ° 09 ’ 7 ”, W 97 ° 3 ’ 38 ”, en nopal podrido, 6 - VIII- 2001, S. Bautista, J. Asiain y J. Márquez ”. Paratypes: same data as holotype (5, MAAS). Mexico: Oaxaca: “ San Juan Chicomesuchitl, Rio Grande, 1436 m, N 17 ° 18 ’ 729 ”, W 96 ° 30 ’ 600 ”, en nopal y mandarina podrida, 16 - XI- 1999, J. Márquez col. ” (1, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977177F3981AFA3D2FA17FE6D.taxon	description	Figs. 5 b, c, 13 f, 15 n, 19 h, 23 e, 31 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977177F3981AFA3D2FA17FE6D.taxon	description	Head: transverse, ratio length / width in males 0.78 (range 0.74 – 0.84), in females 0.86 (range 0.80 – 0.91). Dorsal surface with sulcate longitudinal midline visible in anterior half of head or slightly backward; front slightly foveate at space between antennal insertions. Eyes nearly 0.5 times the cephalic lateral length, not protruding laterally. Antennomeres 4 – 5 elongate, 6 – 10 transverse. Males with mandibles 1.14 times longer than head (range 0.85 – 1.42), in females 0.83 (range 0.77 – 1.00); each with two small, moderately separated teeth (basal and middle); mandibular channel slightly developed, external margin not carinate and internal margin like impressed line extending forward, far exceeding level of middle tooth. Apical palpomere of maxillary and labial palpi slightly longer than preapical palpomere. Males with head 1.13 times wider than pronotum (range 1.03 – 1.20), in females almost equally wide (ratio 0.99, range 0.92 – 1.12). Thorax: each dorsal row of pronotum with by five punctures; pronotum slightly longer than wide (ratio in males 1.11, range 1.06 – 1.15, in females 1.15, range 1.1 – 1.2), as wide at anterior corners as at posterior corners (ratio in males 1.07, range 1.03 – 1.13, in females 1.05, range 1.02 – 1.12). Scutellum with punctures slightly denser than on elytra, where are moderately dense. Prosternum with area next to anterior margin slightly elevated. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly V-shaped, not meeting with margin of intercoxal process laterally. Profemur of males with external row of small, darker spines extending from base to apical third, near level where internal apical spines initiate, which are longer and slenderer than external spines; profemur not widened at apex as in B. bidens. Metafemur of males with spines at ventral surface not clearly arranged in two rows, with large, black and disordered external spines near base; internal spines near base smaller and paler than external spines, arranged in a row reaching nearly 1 / 2 of length of femur (Fig. 13 f). Tarsomeres flattened dorsally. Abdomen: first three visible abdominal tergites with posterior basal transverse carina well developed; adjacent zone slightly or not depressed, with sparse, wide-superficial punctures combined with fine punctures that also cover remaining surface of tergites 1 – 3; fourth visible tergite with punctures as in previous tergites; tergites 5 – 6 only with fine punctures. Visible sternites 1 – 4 with wide-superficial punctures denser than on tergites, covering main part of their surface and combined with fine punctures; sternites 5 – 6 only with fine punctures. Male pregenital sternite with broad V-shaped emargination at posterior margin (Fig. 15 n). Male genital sternite moderately large (2.53 times longer than wide), moderately symmetrical, anterior portion occupying 39 % and posterior portion 61 % of its length, apical emargination deep (Fig. 19 h). Abdominal styli slender. Aedeagus: length 1.55 mm; cone shape; apex moderately acute; apical half notably narrower than basal half; internal sac visible (Fig. 23 e). Variability. In some specimens the apical half of antennae is reddish-brown, the apical antennomere reddish, and antennomere 4 varies in size relative to size of specimen; in two large males, a small ridge or carina was noted near base of first antennomere, on the side facing forward or towards mandibles, which is not observed in females or in small specimens. The basal tooth of each mandible is very small to undiscernible in small specimens. In one specimen, the prosternum is reddish in anterior half and black in posterior half. The metaventrite may be irregularly black with reddish brown; the proportion of black and reddish color of the fifth visible abdominal segment is a little variable, but the black color never reaches the anterior margin or less than half of the segment, and tergite and genital sternite can be black or pale gray. Pregenital sternite of males can be less deeply emarginate at posterior margin. Taxonomic comments. Belonuchus pollens is very similar to B. erichsoni, B. mixtecus and B. rufipennis. In taxonomic comments of the first two species, it has been pointed out how to distinguish them. It is distinguished from B. rufipennis by the black procoxae and mesocoxae, spines of posterior femora of males large, unaligned and not exceeding the basal half, and by the shape and size of aedeagus and genital sternite; B. rufipennis has all coxae reddish, males have two rows of small spines along almost entire internal margin of the metafemur, and the aedeagus and genital sternite are of different size and shape. The syntypes of this species were not studied, but we analized some photos of these specimens (Fig. 5 b; NHM, shared by M. Chani Posse), which together with the information of the original description (Sharp 1885) allowed us to identify this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977177F3981AFA3D2FA17FE6D.taxon	materials_examined	Material examined (nine males, 10 females): Mexico: Hidalgo: “ La Misión, camino al río Moctezuma, N 21 ° 8 ’ 30.6 ”, W 99 ° 5 ’ 49.1 ”, bosque tropical subcaducifolio, trampa de intercepción de vuelo, 23 - VI a 5 - VII- 2017, J. Márquez y A. Lora cols. ” (1, CC-UAEH). “ Pacula, camino Jacala-Pacula, 15.3 km hacia Pacula, selva baja caducifolia, 808 m, N 21 ° 02 ’ 20.3 ”, W 99 ° 16 ’ 32 ”, NTP- 80 (calamar), 7 al 17 - VI- 2008, J. Márquez col. ” (2, CC-UAEH). Morelos: “ Tlayacapan, San José de los Laureles, NTP- 80, localidad 3, bosque mesófilo de montaña perturbado, IV- 1996, J. Márquez col. ” (1, MAAS). “ Tlayacapan, selva baja caducifolia, zona 4, NTP- 80, IV- 1996, J. Márquez y K. Villavicencio cols. ” (1, MAAS). Same data, except: “ X- 1995 ” (1, MAAS). Oaxaca: “ carretera Oaxaca-Tehuantepec, km 93.6 (delante de Totolapan), matorral xerófilo, 1212 m, N 16 ° 40 ’ 667 ” W 96 ° 13 ’ 676 ”, en nopal podrido, 18 - XI- 1999, J. Márquez col. ” (1, MAAS). “ San Mateo Peñasco, en jardín, 1788 m, N 17 ° 09 ’ 7 ”, W 97 ° 3 ’ 38 ”, en nopal podrido, 6 - VIII- 2001, S. Bautista, J. Asiain y J. Márquez ” (1, MAAS). “ km 2 carretera El Camarón-San Carlos Yautepec, 850 m, trampa de intercepción de vuelo, 21 a 22 - agosto- 2003, Q. Santiago y L. Delgado cols. ” (2, IEXA). Puebla: “ km 4 carretera Tepexco – Izúcar de Matamoros, N 18 ° 39´22 ”, W 98 ° 39´53.2 ”, 1350 m, trampa de intercepción de vuelo # 2, 18 - VII- 2015, A. y L. Delgado col. ” (1, IEXA). Tamaulipas: “ Adolfo López Mateos, El Chamalito, trampa de intercepción de vuelo diurna, 15 - IX- 2003, L. Cervantes y Q. Santiago cols. ” (1, IEXA). Veracruz: “ Xalapa, San Antonio Paso del Toro, trampa de intercepción de vuelo # 2, 25 - VII- 2015, K. Cortes y Q. Santiago cols. ” (5, IEXA). Same data, except: “ 19 - IX- 2015 ” (1, IEXA). Same data, except: “ 17 - X- 2015 ” (1, IEXA).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977157F3E81AFA7E6FA03FD68.taxon	description	Figs. 5 d, 13 d, 16 j, 19 i, 23 f, 31 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977157F3E81AFA7E6FA03FD68.taxon	description	Head: transverse; ratio length / width in males 0.81 (range 0.75 – 0.87), in females 0.88 (range 0.85 – 0.92); convex in posterior half of dorsal surface and at posterior corners. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front moderately foveate at space between antennal insertions. Eyes large, more than 0.5 times the cephalic lateral length, slightly protruding laterally. Antennomeres 4 – 5 elongate, 6 – 10 transverse. Males with mandibles almost as long as head (ratio 1.06, range 0.91 – 1.18), females with mandibles shorter than head (ratio 0.80, range 0.73 – 0.85); each with two moderately separated teeth, basal tooth bigger than middle tooth; mandibular channel moderately developed, external margin weakly carinate and internal margin with carinate line only in basal third of its length, extending forward like impressed line beyond level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.5 times longer than preapical palpomere. Head of males slightly wider than pronotum (ratio 1.14, range 1.11 – 1.20), in females head and pronotum almost equally wide (ratio 1.01, range 0.95 – 1.15). Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio in males 1.08, range 1.04 – 1.15, in females 1.14, range 1.08 – 1.23) and almost as wide at anterior corners as at posterior corners (ratio in males 1.09, range 1.07 – 1.12, in females 1.06, range 1.00 – 1.10). Scutellum with punctures denser than on elytra, where are somewhat sparse. Prosternum with anterior area slightly elevated transversally. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly V-shaped, not meeting margin of intercoxal process laterally. Profemur of males slightly widened toward apex, visible only when compared with that of females; external row of spines initiating after basal third and ending before apex, last three or four spines larger than previous spines and spines at internal side; internal row of spines initiating near half length of femur and reaching apex, small darker spines very numerous and close to each other. Metafemur of males with two rows of spines well developed at ventral surface, only near base of femur with some non-aligned spines, both rows can extend almost until apex or 2 / 3 of its length; spines as long and dark as spines of posterior tibiae (Fig. 13 d). Tarsomeres dorsally flattened, although little evident because they are small. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent area slightly depressed; anterior half of each tergite (including depression) with dense wide-superficial punctures that decrease in density toward posterior half, these punctures combined with moderately dense fine punctures; fourth tergite with similar punctures as previous tergites; tergites 5 – 6 only with fine punctures, although on visible segments 4 – 6 (particularly 5) with wide and dark setae that are sparse in other segments; visible sternites 1 – 4 with punctures as in tergites 1 – 3, but wide-superficial punctures denser. Male pregenital sternite moderately emarginate at posterior margin (Fig. 16 j). Male genital sternite very elongate (3.19 times longer than wide), moderately symmetrical, anterior portion occupying 33 % and posterior portion 67 % of its length, apical emargination deep (Fig. 19 i). Abdominal styli slender. Aedeagus: length 1.1 mm; apical half of elongate shape and basal half of oval shape; apex subacute; basal half evidently wider than apical half; internal sac visible (Fig. 23 f). Variability. In addition to the variation included in the description related to measurements and ratios, it was observed that in specimens of the central and northern parts of the country, antennomeres 1 – 2 and apical segment are almost as dark as remaining antennomeres, while in specimens from other states they are noticeably paler. Punctures in each dorsal row of prontoum vary from 5: 6, 6: 5 to 6: 6. Scutellum of some specimens, presumably tenerals, is almost reddish or brown instead of black. The long and dark setae of visible abdominal segments 4 – 6 may be lacking to variable extent because they are often rubbed off. Posterior margin of male pregenital sternite varies in the depth of the emargination, from very weak to moderate. Taxonomic comments. This species is similar to B. mixtecus and B. pollens, and their main differences have been indicated in the taxonomic comments of these species. The type material of this species was not studied, but we used the detailed taxonomic information given by Smetana (1995), so we had no doubts about the identification of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977157F3E81AFA7E6FA03FD68.taxon	materials_examined	Material examined (151 males, 136 females): Mexico: Chiapas: “ Cacaohatán, Unión Roja, La Boquilla, 550 m, NTP- 80, 6 - VIII- 84, A. López col. ” (19, IEXA). “ carretera Tuxtla Gutiérrez- San Cristóbal de Las Casas, km 30.7, selva mediana perturbada, 961 m, N 16 ° 45 ’, W 92 ° 57 ’, NTP- 80 calamar, 20 - XI a 3 - XII- 1999, J. Márquez col. ” (3, MAAS). “ La Victoria, ex carrion trap, 17 - december- 1982, M. A. Morón col. ” (6, IEXA). “ Tapachula, Ejido Raimundo Enríquez, 70 m, N 14 ° 51 ’ 52.18 ”, W 92 ° 19 ’ 56.66 ”. Toma 6 / Rata 2 (lluvia). 3 - VII- 2013, Y. Recinos y E. Chamé cols. ” (1, CC-UAEH). Same data, except: “ Toma 16 / Rata 1 (lluvias). 6 - VII- 2013 ” (1, CC-UAEH). Same data, except: “ Toma 26 / Rata 2 (lluvias). 28 - II- 2013 ” (1, CC-UAEH). Same data, except: “ Toma 9 / Rata 2 (lluvias). 4 - VII- 2013 ” (1, CC-UAEH). Guerrero: “ Acahuizotla, Barranca Las Juntas, 900 m, trampa de intercepción de vuelo, 27 a 29 - VIII- 2003, Q. Santiago y L. Delgado cols. ” (1, IEXA). Hidalgo: “ Atlapexco, rio Atlapexco, cultivos, 168 m, N 21 ° 00 ’ 2.6 ”, W 98 ° 20 ’ 52.2 ”, en tronco, 9 - XII- 2005, J. Márquez, F, Ramírez y J. Asiain cols. ” (1, CC- UAEH). “ Chapulhuacán, Arroyo Blanco, salva alta, 239 m, N 21 ° 09.286 ’, W 99 ° 00.331 ’, NTP- 80 # 2, 30 - III a 06 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (3, CC-UAEH). “ Chapulhuacán, Arroyo Blanco, salva alta, 276 m, N 21 ° 09.299 ’, W 99 ° 0.317 ’, NTP- 80 # 1, 30 - III a 06 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (3, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo, 1 a 4 - VI- 2007, J. Asiain y J. Márquez cols. ” (4, CC-UAEH). Same data, except: “ NTP- 80 (calamar), 14 a 17 - VII- 2007, J. Asiain, A. P. Martínez, I. A. Rodríguez y J. Márquez cols. ” (1, CC-UAEH). “ Chapulhuacán, Puerto del Zopilote, bosque mesófilo de montaña, 1134 m, N 21 ° 09.9 ’ 7.9 ”, W 98 ° 55.8 ’ 04.0 ”, NTP- 80 (calamar) # 10, 28 - VIII a 11 - IX- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2 ” (1, CC-UAEH). “ Huautla, Acatepec, selva baja, 315 m, N 20 ° 56 ’ 35.91 ”, W 98.18 ° 16 ’ 15.85 ”, en mango, 9 - VI- 2006, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Huautla, 2 km NW de Tohuaco Amatzintla, N 21 ° 07´23 ”, W 98 ° 16´51 ”, bosque tropical subcaducifolio, trampa cebada con champiñones, 17 a 28 - IV- 2015, R. Ramírez y J. Márquez cols. ” (25, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3 ” (1, CC-UAEH). “ Huehuetla, Rio Blanco, bosque tropical perennifolio, 588 m, UTM (WG- 384), 145 94809 E, 2257303 N, NTP- 80 (calamar), 1 al 30 - V- 2010, C. Berriozábal col. ” (10, CC-UAEH). “ La Misión, Los Naranjos, Palo Hueco, BMM, 1276 m, N 21 ° 08 ’ 06 ”, W 99 ° 05 ’ 02 ”, NTP- 80 (calamar) # 8, 10 al 24 - III- 2011, J. Márquez col. ” (5, CC-UAEH). “ La Misión, Lomas del Pericón, bosque mesófilo de montaña, 1377 m, N 21 ° 6.0 ’ 46.0 ” W 99 ° 6.0 ’ 15.6 ”, NTP- 80 (calamar) # 8, 26 - VIII al 9 - IX- 2011, J. Márquez col. ” (1, CC-UAEH). “ La Misión, Lomas del Pericón, bosque mesófilo de montaña perturbado, 1377 m, N 21 ° 60 ’ 46.0 ”, W 99 ° 6.0 ’ 15.6 ”, NTP- 80 (calamar), 8 al 16 - III- 2008, J. Márquez y J. Asiain col. ” (3, CC-UAEH). “ La Misión, bosque mesófilo de montaña, 1334 m, N 21 ° 06 ’ 202 ”, W 99 ° 06 ’ 291 ”, NTP- 80 (calamar) # 2, 29 - III al 05 - IV- 2009, J, Márquez, M. Rivera, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ La Misión, Los Naranjos, Palo Hueco, bosque mesófilo de montaña, 1276 m, N 21 ° 08 ’ 06 ”, W 99 ° 05 ’ 02 ”, NTP- 80 (calamar), 10 al 24 - III- 2011, J. Márquez col. ” (19, CC- UAEH). “ La Misión, camino al río Moctezuma, N 21 ° 8 ’ 30.6 ”, W 99 ° 5 ’ 49.1 ”, bosque tropical subcaducifolio, trampa de intercepción de vuelo, 23 - VI a 5 - VII- 2017, J. Márquez y A. Lora cols. ” (5, CC-UAEH). Same data except: “ en NTP- 80 (calamar) ” (5, CC-UAEH). “ Pacula, camino Jacala-Pacula, 15.3 km hacia Pacula, selva baja caducifolia, 808 m, N 21 ° 02 ’ 20.3 ”, W 99 ° 16 ’ 32 ”, en trampa de intercepción de vuelo, 7 al 17 - VI- 2008, J. Márquez, I. Garrido y M. García cols. ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar), 7 a 17 - VI- 2008, J. Márquez col. ” (12, CC- UAEH). “ Pacula, camino al Membrillar del Fraile, río Moctezuma, N 99 ° 23´28 ”, W 21 ° 5´26.8 ”, 903 m, vegetación riparia, NTP- 80 (calamar), 19 - I a 25 - II- 2010, J. Islas col. ” (7, CC-UAEH). “ Tenango de Doria camino a La Viejita, bosque mesófilo de montaña, 1647 m, N 20 ° 19.0 ’ 37.9 ”, W 98 ° 14 ’ 39.7 ”, NTP- 80 (calamar), 12 - VIII- 2010, C. Cornejo col. ” (2, CC-UAEH). “ Tepehuacán de Guerrero, Chilijapa, bosque mesófilo de montaña, 1401 m, N 21 ° 01.2 ’ 5.1 ”, W 98 ° 51.8 ’ 2.1 ”, trampa de intercepción de vuelo # 2, 11 al 25 - III- 2011, J. Márquez col. ” (1, CC-UAEH). “ Tlanchinol camino a Apantlazol, El Pozo, bosque mesófilo de montaña, 1391 m, N 20 ° 59 ’ 6.73 ”, W 98 ° 37 ’ 39.86 ”, NTP- 80 (calamar) # 5, 16 a 30 - IV- 2011, J. Márquez col. ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2 ” (1, CC-UAEH). Jalisco: “ Casimiro Castillo, selva alta perenifolia, en excremento vacuno, 25 - IX- 1995. ” (1, MAAS). “ La Huerta, carretera Barra de Navidad, Puerto Vallarta, Estación Biológica de Chamela, selva baja caducifolia, 77 m, N 19 ° 27 ’ 2.2 ”, W 105 ° 1 ’ 33 ”, en excremento, 10 - XIII- 2005, S. Bautista col. ” (1, CC-UAEH). “ La Huerta, Estación Biológica de Chamela, selva baja caducifolia, 77 m, N 19 ° 27 ’ 2.2 ”, W 105 ° 1 ’ 33 ”, en excremento, 11 al 12 - VII- 2006, S. Bautista y S. Pulido cols. ” (8, CC-UAEH). “ Melaque, Coastecomate, selva baja caducifolia, en necrotrampa temporal (calamar), 23 - IX- 1995, J. L. Navarrete y J. Márquez cols. ” (1, MAAS). Morelos: “ Ciudad Ayala, Unidad 10 de abril, 1360 m, trampa de intercepción de vuelo, 26 a 31 - VII- 2003, A. y L. Delgado cols. ” (10, IEXA). “ Mexicapa, bosque de pino, NTP- 80 calamar, zona 3, 27 - XI- 1993, A. Soria, C. Cabello y E. Córdoba cols. ” (1, MAAS). “ Tlayacapan, San José de los Laureles, NTP- 80, localidad 3, bosque mesófilo de montaña perturbado, V- 1996, J. Márquez col. ” (2, MAAS). Same data, except: “ localidad 1, bosque de pino-encino, IX- 1995, J. Márquez col. ” (3, MAAS). Same data, except: “ IV- 1996, K. Villavicencio y J. Márquez cols. ” (1, MAAS). “ Tlayacapan, San José de los Laureles, camino a Amatlán, bosque de pino-encino, 1874 m, N 18 ° 58.5 ’, W 99 ° 0.5 ’, NTP- 80 (calamar), IX- 1995, J. Márquez col. ” (1, MAAS). “ Tlayacapan, en detritos de A. mexicana, 25 - I- 1999, J. Márquez col. ” (1, MAAS). “ Tlayacapan, Santa Catarina, selva baja caducifolia y huertos, en hojarasca, 16 - VIII- 1998, J. Márquez y R. Toledo cols. ” (1, MAAS). Puebla: “ Tlacuilotepec, cerca del río San Marcos, N 20 ° 19 ’ 22.5 ”, W 98 ° 02 ’ 35.4 ”, bosque tropical subcaducifolio, trampa con fruta, 13 a 25 - X- 2018, J. Márquez y J. D. Silva cols. ” (1, CC-UAEH). Same data, except: “ NTP- 80, 26 - VI a 17 - VII- 2018, J. D. Silva-Hurtado col. ” (1, CC-UAEH). “ Xicotepec de Juárez, Hidroeléctrica Plata, selva mediana, 457 m, en plantas, 5 - X- 2002, en plátano podrido, J. Asiain y J. Márquez cols. ” (1, MAAS). “ Xicotepec de Juárez, Hidroeléctrica Patla, bosque mesófilo de montaña, en necrotrampa temporal (calamar), 27 - III- 1998, O. Pérez col. ” (1, MAAS). “ km 4 carretera Tepexco - Izúcar de Matamoros, N 18 ° 39´22 ”, W 98 ° 39´53.2 ”, 1350 m, trampa de intercepción de vuelo # 1, 18 - VII- 2015, A. y L. Delgado cols. ” (11, IEXA). Querétaro: “ Ayutla, Arroyo Seco, cerca de las cabañas Las Adjuntas, N 21 ° 24 ’ 11.1 ”, W 99 ° 34 ’ 38.9 ”, bosque tropical caducifolio, trampa de intercepción de vuelo, 15 a 17 - VI- 2016, J. Márquez col. ” (1, CC-UAEH). Quintana Roo: “ A. N. P. Yum Balam, 2014, N 21.36024 °, W 87.410656 °, 169 mlnm, E. Chamé col. “ (1, CC-UAEH). “ A. N. P. Yum Balam, sitio 1, necrotrampa, 04 - 09 - 2016 ” (1, CC-UAEH). Tamaulipas: “ carretera antigua Ciudad Victoria, Huamave, camino a La Mina Virgen, selva baja caducifolia, 440 m, N 23 ° 42 ’ 9.4 ” W 99 ° 12 ’ 57.6 ”, en excremento vacuno, 2 - XI- 2004, J. Márquez col. ” (1, CC-UAEH). Veracruz: “ Catemaco, Pipiapan, Parque de la Flora y Fauna Silvestre Tropical, 600 m, necrotrampa, 28 - X- 1999, A. Díaz col. ” (1, IEXA). “ Córdoba, San Rafael Calería, Ojo de Agua, N 18 ° 57 ’ 15 ”, W 96 ° 56 ’ 24 ”, selva mediana subcaducifolia, 1127 m, NTP- 80 (calamar), 20 - III a 17 - IV- 1999, Q. J. Santiago, J. Márquez y J. Asiain cols. ” (1, MAAS). “ Huatusco, Coxcontla, bosque mesófilo de montaña perturbado, 1250 msnm, NTP- 80 (calamar) # 746, 3 - VI- 1995, M. A. Pensado y Q. Santiago cols. ” (1, MAAS). Same data, except: “ NTP- 80 (calamar) # 202, 22 - X a 19 - XI- 1994 ” (1, MAAS). “ Ilamatlán, Xococapa, bosque tropical subperenifolio, 397 m, N 20 ° 48 ’ 24.0 ”, W 98 ° 20 ’ 24.6 ”, NTP- 80 (calamar) # 4, 5 - III a 1 - IV- 2006, F. Ramírez col. ” (4, CC- UAEH). “ Totutla, Mata Oscura, 1 km S de Zacuapan, selva mediana subcaducifolia, 921 m, N 19 ° 12 ’ 23 ”, W 96 ° 50 ’ 32 ”, NTP- 80 (calamar), 20 - II al 19 - III- 1999, Q. Santiago y J. Márquez cols. ” (6, MAAS). “ Totutla, El Encinal, bosque de encino perturbado, 750 msnm, NTP- 80 (calamar) # 683, 6 - V al 3 - VI- 1995, M. A. Pensado y Q. Santiago cols. ” (1, MAAS). “ Xalapa, San Antonio Paso del Toro, trampa de intercepción de vuelo # 1, 4 - IV- 2015, L. Delgado col. ” (8, IEXA). Same data, except: “ 2 a 30 - V- 2015, K. Cortes y Q. Santiago cols. ” (15, IEXA). Yucatán: “ Conkal, NTP- 80, 26 - II a 26 - III- 2002, L. Peraza col. ” (33, IEXA). “ Tzucacab, Tigre Grande, NTP- 80, 20 - VIII a 17 - IX- 2002, L. Peraza col. (5, IEXA). Same data, except: “ 14 - I a 11 - II- 2002 ” (15, IEXA). Group 3: xanthomelas Included species: B. basiventris (Sharp, 1885), B. connexus (Say, 1830), B. longitarsus sp. nov., B. rufiventris (Sharp, 1887), and B. xanthomelas Solsky, 1868.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977157F3E81AFA7E6FA03FD68.taxon	diagnosis	Diagnosis of the xanthomelas group: head without temporal carina; males with mandibles expanded at base (Fig. 10 c), mandibles as long as head or slightly longer (Fig. 10 c); females with mandibles shorter than head (Fig. 6 c); pronotum with five or less punctures in each dorsal row; elytra reddish; trochanters and femora of posterior legs without modifications in both sexes; tarsomeres somewhat flattened dorsally; abdomen reddish with black or completely black; aedeagus with reduced paramere (Figs. 23 g – i).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977127F3D81AFA4E3FCE6FA9D.taxon	description	Figs. 5 e, f, 16 k, 19 j, 23 g, 30 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977127F3D81AFA4E3FCE6FA9D.taxon	description	Head: oval shape, dorsally slightly convex, wider than long (ratio in males 0.80, range 0.76 – 0.84, in females 0.88, range 0.81 – 0.92). Dorsal surface with microsculpture like wavy lines fainty visible near front, along margin of eyes and base of antennae; punctures less dense than in majority of species, with similar distribution as in other species; sulcate longitudinal midline faintly visible only at front; front weakly foveate between antennal insertions. Eyes nearly 0.5 times the cephalic lateral length, slightly protruding laterally. Antennomere 1 as long as antennomeres 2 – 3 combined, antennomeres 4 – 5 elongate, 6 as long as wide, 7 – 10 transverse. Mandibles as long as head in males (ratio 1.0, range 0.90 – 1.12), and shorter than head in females (ratio 0.84, range 0.77 – 0.88); mandibles of males widened at base, in females not widened at base; each mandible with two well separated teeth (basal and middle) of similar size; mandibular channel well developed, external margin carinate, internal margin like impressed line extending forward slightly beyond level of middle tooth. Apical palpomere of maxillary palpi 1.5 times longer than subapical palpomere. Apical palpomere of labial palpi slightly longer than preapical palpomere. Males with head 1.13 times wider than pronotum (range 1.04 – 1.19), in females 1.03 times (range 1.00 – 1.04). Thorax: pronotum smooth, without visible microsculpture; each dorsal row with five punctures; pronotum slightly longer than wide (ratio in males 1.15, range 1.11 – 1.20, in females 1.17, range 1.14 – 1.20) and almost as wide at anterior corners as at posterior corners (ratio in males 1.04, range 1.00 – 1.08, in females 1.0, without variation). Scutellum with punctures slightly denser than punctures on elytra, punctation of elytra less dense and surrounded by brown coloration, which contrasts with reddish smooth surface. Prosternum with area near to anterior margin slightly elevated transversally and without posterior constriction or line. Intercoxal process of mesoventrite shieldshaped, but sides toward apex not as straight as in many species; transverse discal ridge moderately developed, broadly V-shaped, not touching margin of intercoxal process laterally. Profemur of males without internal margin or only discernible near apex, there with five to six large aligned spines; external margin with row of spines only in anterior third, not extending until apex, middle spines longer than lateral spines, and longer than apical spines of internal margin. Posterior legs of males and females without modifications. Tarsomeres flattened dorsally, but slightly visible because they are somewhat narrow. Abdomen: first two visible tergites with posterior basal transverse carina well developed, but in visible tergite 3, posterior basal transverse carina diffuse or not completely developed; adjacent area moderately depressed, with wide-superficial punctures moderately dense combined with fine punctures; posterior half of visible tegites 1 – 3 with less dense wide-punctures; visible tergite 4 with punctures as on previous tergites; visible tergites 5 – 6 only with fine punctures. Visible sternites 1 – 3 with wide-superficial punctures combined with fine punctures on entire surface; visible sternites 4 – 5 with wide punctures that are less dense posteriorly; sixth visible sternite only with fine punctures. Male pregenital sternite with distinct, broadly U-shaped or V-shaped emargination at posterior margin (Fig. 16 k). Male genital sternite short (2.35 times longer than wide), very asymmetrical, anterior portion occupying 33 % and posterior portion 67 % of its length, apical emargination deep (Fig. 19 j). Abdominal styli slender. Aedeagus: length 1.0 mm; cone-shaped, sides not as homogeneously narrowed toward very acute apex; basal half moderately wider than apical half, latter gradually narrow toward apex; internal sac indistinctly visible (Fig. 23 g). Variability. Great variation was observed in the extension and intensity of the black or dark color of first two visible abdominal segments; lighter portion of segment 2 and entire segment 3 are brown (darker than elytra) rather than reddish; brown coloration around punctures of elytra is not present in all specimens; prosternum may be reddish in anterior half and black or brown in posterior half, all brown or all black; posterior coxae can be from totally black to reddish-brown; posterior basal transverse carina of visible tergite 3 variably developed, but always less than in two previous tergites. Taxonomic comments. This species can be confused with B. xanthomelas, but B. basiventris has the first two visible abdominal segments mostly black, with some minor reddish portions, entire ventral part of thorax black, male pregenital sternite remarkably emarginate at posterior margin like extended U-shaped, and aedeagus with basal half moderately wider than apical half (Figs. 16 k, 23 g). Conversely, B. xanthomelas has the first four visible abdominal segments and anterior border of fifth reddish, ventral surface of thorax not completely black, because the ventral surface of thorax (sterna) are black at center and peripheral parts are reddish or even entire sterna can be reddish, male pregenital sternite moderately emarginate at posterior margin and aedeagus narrower at base, apex very acute, in lateral view, it is notably wider in basal half (Figs. 16 m, 24 b). The syntypes of this species were not studied, but we analyzed some photos of these specimens (Fig. 5 e; NHM, shared by M. Chani Posse), which together with the information of the original description (Sharp 1885) allowed us to identificaty this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977127F3D81AFA4E3FCE6FA9D.taxon	materials_examined	Material examined (20 males, 13 females): Mexico: Hidalgo: “ Huasca de Ocampo, San Miguel Regla, bosque Las Truchas, bosque de encino, 2073 m, N 20 ° 13 ’ 0.3 ”, W 98 ° 33 ’ 28.6 ”, en hojarasca cernida, 14 - IV- 2007. J. Márquez y J. Asiain, cols. ” (1, CC-UAEH). Morelos: “ camino a Mexicapa, bosque mesófilo de montaña perturbado, NTP- 80 (calamar), zona 6, 6 - VI- 1993, A. Soria y E. Córdoba cols. ” (3, MAAS). “ Ocuilan, camino a Mexicapa, bosque de pino, trampa 1, VIII- 1993, J. Márquez col. ” (2, MAAS). Same data, except: “ VI- 1993 ” (5, MAAS). “ Tlayacapan, en detritos de A. mexicana, 20 - VII- 1992, J. Márquez col. ” (2, MAAS). “ Tlayacapan, selva baja caducifolia, zona 4, NTP- 80, IV- 1996, J. Márquez y K. Villavicencio cols. ” (2, CC-UAEH). “ Tlayacapan, San José de los Laureles, en hojarasca, 28 - V- 2000, J. Márquez y J. Asiain cols. “ (18, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977117F4281AFA3F6FC3DFD29.taxon	description	Figs. 5 g, h, 10 c, 16 – l, 19 k, 23 h, 32 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977117F4281AFA3F6FC3DFD29.taxon	description	Head: transverse, ratio length / width in males 0.78 (range 0.73 – 0.82), in females 0.88 (range 0.85 – 0.92). Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front weakly foveate between antennal insertions. Eyes somewhat small, less than 0.5 times the cephalic lateral length, slightly protruding laterally. Antennomere 4 as long as wide, antennomeres 5 – 10 transverse. Males with mandibles 1.15 times longer than head (range 1.08 – 1.27), in females shorter than head (ratio 0.84, range 0.77 – 0.88); males with mandibles notably expanded at base, each with two clearly separated teeth (basal and middle) of almost equal size; mandibular channel well developed, external margin carinate and internal margin like conspicuous carinate line, extending forward beyond level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Male with head 1.22 times wider than pronotum (range 1.15 – 1.29), in females almost equally wide (ratio 1.05, range 1.00 – 1.08). Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio in males 1.13, range 1.11 – 1.16, in females 1.18, range 1.11 – 1.23); in males, slightly wider at anterior corners than at posterior corners (ratio 1.10, range 1.06 – 1.12), in females almost equally wide (ratio 1.04, range 1.02 – 1.08). Scutellum with punctures denser than elytra, elytral punctation moderately dense. Prosternum with area adjacent to anterior margin slightly elevated transversally and delimited backward by an impressed line. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly U-shaped, meeting margin of intercoxal process laterally. Profemur of males with internal margin only discernible near apex, there with five to six aligned spines of moderate size; external margin with row of spines only in anterior third, not reaching apex, spines in middle part of row larger than spines at sides, even larger than apical spines of internal margin. Posterior legs of males and females without modifications. Tarsomeres flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed, which is curved at sides of tergites 1 – 2 and straight in tergite 3; depressed adjacent area slightly deeper and narrower than in B. xanthomelas, but with punctures on tergites and sternites as has been described for B. xanthomelas; anterior half of sternites and near margins of tergites with wrinkled microsculpture. Male pregenital sternite slightly emarginate at posterior margin (Fig. 16 – l). Male genital sternite moderately elongate (2.76 times longer than wide), very asymmetrical, anterior portion occupying 34 % and posterior portion 66 % of its length, apical emargination deep (Fig. 19 k). Abdominal styli slender. Aedeagus: length 1.1 mm; cone-shaped, sides abruptly narrowed subapically toward sharply point tip; basal half moderately wider than apical half, although in lateral view, basal half is notably widened; internal sac visible (Fig. 23 h). Variability. The color of legs ranges from reddish in specimens from central and northern Mexico, to almost black in specimens from southern and southwestern states. In some specimens, the entire ventral portion of the body and abdomen are dark brown rather than black. The anterior borders of first three or four visible abdominal segments may be lighter (brown or reddish) than the rest of the segment and in other specimens the posterior border may be lighter. In small males, the emargination of the pregenital sternite is less noticeable than in large males. The rest of the variation is included in the description, in addition to the general variation related to the sex and size of the specimens. Taxonomic comments. Belonuchus connexus is rarely confused with any other species in this group because of the black body, with only the elytra and (usually) legs reddish, which may also be almost black. Say (1830: 35, 1834: 448) described B. connexus (as Staphylinus) and commented that it is very similar to B. ephippiatus (as Staphylinus), which he described a paragraph earlier. He mentions that the main differences between both species is that B. connexus is smaller (just over 9 mm), has cinnamon red legs like the color of the elytra, and a black abdomen, without an iridescent dark blue reflection. On the other hand, B. ephippiatus is larger (more than 15 mm), the legs are black and the abdomen has a dark blue iridescent shine. The collection records that we have of these two species indicate that they are sympatric, frequently coexisting in decomposing cacti in semiarid sites, so we assume that the original description of these two species followed by one another may be due to being collected together. The Say type material is known to be destroyed (Smetana 1995), so it was not possible to review the type specimen (s) of B. connexus. Despite this, the characters included in the original description, as well as the sympatric distribution that it presents with B. ephippiatus, allow us to propose that B. xanthopus as described by Solsky (1868) is the same species as B. connexus since Solsky mentions similar characteristics. Although a photo of the holotype of B. xanthopus was available, its usefulness was limited because few diagnostic characters are visible as it is a possibly teneral female; however, the information in the original description, along with the photo, is sufficient for the proposed synonym. Sharp (1885), when referring to the differences between B. xanthopus and B. celatus, the latter of which is also proposed here as a synonym of B. connexus, stated the following: “ This species is distinguished from P. xanthopus always only because of the dark color of the legs. The sexual characteristics are the same in these species as they are in P. xanthomelas and P. basiventris ” (Sharp 1885: 420). The revised specimens from Morelos and Oaxaca have darker legs than those from other states, but all the other characters, including the aedeagus, body length, pregenital and genital sternites, etc., are the same. Therefore, the dark or reddish legs can be considered as (possibly geographic) variation. The following are some relevant characters coincident in the original descriptions of B. connexus (Say, 1830), B. xanthopus Solsky, 1868, and B. celatus (Sharp, 1885), which support the synonymies here proposed: total body length 7 – 11 mm; body black shiny, elytra and legs red, mandibles, antennae and abdominal segments piceous-red, scutellum piceous-black; male mandibles expanded; each dorsal row of pronotum formed by five punctures; femora of anterior legs with long spines along the margin; abdomen with sparse punctures; and sixth ventral segment emarginate.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977117F4281AFA3F6FC3DFD29.taxon	materials_examined	Type material. The holotype or syntypes of B. connexus are considered destroyed (Smetana 1995), so it is not possible to study them. Two photographs (ventral view and dorsal view) of the female holotype of B. xanthopus, probably teneral, provided by A. Kovalev (Zoological Institute of the Russian Academy of Sciences) were reviewed. The type material of B. celatus was not studied, although a photograph of the lectotype designated by Chani-Posse et al. (2018 b) was analyzed. Additional material examined (94 males, 87 females): Mexico: Aguascalientes: “ San José de Gracia, Estación Biológica Agua Zarca, bosque de encino y matorral espinoso, 2200 m, N 22 ° 5 ’ 30 ”, W 102 ° 34 ’ 45 ”, en cactácea descompuesta, 23 - VII- 2015, J. A. Escoto-Moreno, J. Escoto-Rocha y J. Márquez cols. (2, CC-UAEH). Hidalgo: “ Acatlán, Loma Larga, El Llano, cultivos de encinos y matorral xerófilo, 2097 m, N 20 ° 16 ’ 13 ”, W 98 ° 28 ’ 18 ”, en nopales podridos, 13 - VII- 2010, J. Asiain, D. López y J. Márquez cols. ” (5, CC- UAEH). Same data, except: “ NTP- 80 (calamar) 13 al 20 - VII- 2010, J. Márquez y J. Asiain cols. ” (11, CC-UAEH). “ Actopan, camino a La Magdalena, matorral xerófilo perturbado, 2236 m, N 20 ° 17 ’ 39.1 ”, W 98 ° 53 ’ 13.6 ”, en nopal podrido, 31 - X- 2007, J. Márquez, J. Asiain, Z. Huerta y C. Pedraza cols. ” (2, CC-UAEH). “ Atotonilco el Grande, 3 km NE de Montecillos, bosque Juniperus-Quercus, N 20 ° 18 ’ 9 ”, W 98 ° 36 ’ 17 ”, trampa de intercepción de vuelo, 12 al 19 - VII- 2010, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Atitalaquia, Texas, UTM 14 Q 0481484 - 2214345, 2,210 m, matorral xerófilo con cultivo de maíz y alfalfa, en NTP- 80, 25 - VIII a 10 - IX- 2009, J. Islas col. ” (5, CC-UAEH). “ Cardonal, Grutas de Tolantongo, cultivo de aguacate, en fruto podrido, 17 - VII- 1994, J. Márquez col. ” (1, MAAS). “ Huasca de Ocampo, Sta. María Regla alrededores del rio cultivos y Juniperus, en nopales podridos, 27 - VIII- 2014, J. Márquez col. ” (1, CC-UAEH). “ Ixmiquilpan, La Flor, N 20 ° 25.419´, W 99 ° 8.315´, 1839 m, matorral xerófilo, NTP- 80 (calamar), 27 - VIII a 8 - IX- 2009, J. Islas col. ” (2, CC-UAEH). “ Barranca de Metzquitlitlan, matorral xerófilo, en biznaga podrida, 14 - II- 1992, J. Márquez col. ” (5, MAAS). “ Barranca de Meztquititlán, matorral xerófilo, en biznaga podrida, 14 - II- 1992, J. Márquez col. ” (4, MAAS). “ Mineral de la Reforma, Colonia Carboneras, matorral xerófilo y cultivos, en composta, 7 - VII- 2003, L. Garduño col. ” (1, CC-UAEH). “ Mineral de la Reforma, cerca de Pachuquilla camino a la Mina, matorral xerófilo, en nopales podridos, 28 - V- 2009, J. Bueno y J. Márquez cols. ” (2, CC-UAEH). “ Mineral de la Reforma, Colinas de Plata, N 20 ° 4´43.4 ”, W 98 ° 43´46.4 ”, en composta de jardín, 4 - IX- 2016, J. Asiain col. ” (3, MAAS). “ Tasquillo, delante de Motho, matorral xerófilo, 1652 m, N 20 ° 32 ’ 13.1 ”, W 99 ° 16 ’ 43.2 ”, cascara de nuez, 3 - IX- 2005, J. Márquez, F. Ramírez y J. Asiain cols. ” (1, CC-UAEH). “ Tetepango, UTM 14 Q 0484780 - 2221394, 2,152 m, matorral xerófilo, NTP- 80 (cal.), 25 - VIII a 10 - IX- 2009, J. Islas col. ” (4, CC-UAEH). “ Pachuca, en composta, 1320 m, IX- 2003, L. Garduño col. ” (2, CC-UAEH). “ Pacula, Puerto Grande, bosque de encino, 2109 m, N 20 ° 53.850 ’, W 99 ° 19.562 ’, NTP- 80 # 3, 28 - III al 04 - IV- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (2, CC-UAEH). Same data, except: “ NTP- 80 # 1 (calamar) ” (1, CC-UAEH). Same data, except: “ NTP- 80 # 2 (calamar) ” (3, CC-UAEH). “ Santiago de Anaya, El Encinal, N 20 ° 26 ’ 56.0 ”, W 98 ° 55 ’ 20.5 ”, matorral xerófilo y encinos, trampa cebada con nopales fermentados, 24 - VI a 1 - VII- 2018, F. M. Gómez e I. S. Hernández cols. ” (1, CC-UAEH). Same data, except: “ 18 a 25 - VII- 2018 ” (2, CC-UAEH). “ Singuilucan, Matías Rodríguez, N 20 ° 3.734 ’, W 98 ° 33.136 ’, bosque de pino-encino, 2740 m, en troncos con hongos, 8 - IV- 2007, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Tepatitlán, Presa Endho, Pedro Ma. Anaya, N 20 ° 9.621´, W 99 ° 21.874´, 2025 m, matorral xerófilo y cultivo de maíz, NTP- 80 (calamar), 26 - VIII a 10 - IX- 2009, J. Islas col. ” (1, CC-UAEH). “ Zempoala, La Trinidad, matorral xerófilo, 2452 m, N 19 ° 57.697 ’, W 98 ° 43.936 ’, NTP- 80 (carne de cerdo) 4 al 25 - VIII- 2004, G. Pajas y J. Márquez col. ” (1, CC-UAEH) “ Zempoala, Mina San Juan Tepemazalco, matorral xerófilo, 2200 msnm, N 19 ° 54 ’ 29.3 ”, W 98 ° 43 ’ 47.5 ”, semana 4, 4 al 30 - IV- 2007, NTP- 80 (carne de cerdo), T 2, Z. Huerta y J. Márquez cols ”. (1, CC-UAEH). “ Zempoala, Sierra de Pitos, cerca de Mina San Juan Tepemazalco, matorral xerófilo, 2550 m, N 19 ° 54 ’, W 98 ° 43 ’, en nopales podridos, 10 - IX- 2002, J. Asiain y J. Márquez cols. ” (3, CC-UAEH). “ Zempoala, La Trinidad, matorral xerófilo, 2452 msnm, N 19 ° 57.697 ’, W 98 ° 43.936 ’, NTP- 80 (carne de cerdo) 4 al 25 - VIII- 2004, G. Pajas y J. Márquez col. ” (2, CC-UAEH). “ Zempoala, La Trinidad, matorral xerófilo, 2459 msnm, N 19 ° 57 ’ 605 ”, W 98 ° 43 ’ 055 ”, NTP- 80 (carne de cerdo) 4 al 11 - VIII- 2004, T 6, G. Pajas y J. Márquez cols. ” (1, CC- UAEH). “ Zimapán, P. N. Los Mármoles, Trancas, bosque de pino-encino, 2444 m, N 20 ° 48 ’ 12.222 ”, W 99 ° 14 ’ 41 ”, en nopal podrido, 18 - IX- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (2, CC-UAEH). Same data, except: “ NTP- 80 (calamar), 10 - X al 13 - XI- 2007 ” (1, CC-UAEH). “ P. N. Los Mármoles, Zimapán, Minas Viejas, bosque de encino, 1897 m, N 20 ° 55 ’ 23.7 ”, W 99 ° 12 ’ 28 ”, en excremento, 20 - X- 2006, J. Márquez y J. Asiain cols. ” (3, CC-UAEH). Morelos: “ Tlayacapan, San José de los Laureles, localidad 5, cultivos de temporal, NTP- 80, X- 1995, K. Villavicencio y J. Márquez cols. ” (3, MAAS). Same data, except: “ localidad 3, bosque mesófilo de montaña perturbado, IV- 1996, J. Márquez col. ” (1, MAAS). “ Tlayacapan y Tlalnepantla camino a San José de los Laureles, cultivo temporal, en nopales podridos, 15 - VIII- 1998, R. Toledo y J. Márquez cols. ” (1, MAAS). “ Tlayacapan, selva baja caducifolia, zona 4, NTP- 80, VII- 1996, J. Márquez y K. Villavicencio cols. ” (1, MAAS). Same data, except: “ III- 1996 ” (1, MAAS). Oaxaca: “ San Mateo Peñasco, en jardín, 1788 m, N 17 ° 09 ’ 7 ”, W 97 ° 3 ’ 38 ”, en nopal podrido, 6 - VIII- 2001, S. Bautista, J. Asiain y J. Márquez cols. ” (4, MAAS). “ San Juan Chicomesuchitl, Rio Grande, 16 - IX- 1999, en nopal y mandarina podridos, J. Márquez col. ” (m 1, MAAS). “ Zaachila, 21 - VIII- 37, Mex, 4500 ft / A. R. Mead collector ” (m 2, f 1, FMNH). Querétaro: “ Ezequiel Montes, Bernal, El Descanso, matorral xerófilo, 2100 m, 5 - III- 1999, en nopales podridos, S. Arenas y J. Márquez col. ” (8, MAAS; 5, CC-UAEH). Same data, except: “ 3 - III- 1999, J. Márquez col. ” (57, MAAS). Same data, except: “ El Puerto, 5 - III- 1999, NTP- 80 (pescado), A. Romero y J. Márquez col. ” (10, MAAS). “ Ezequiel Montes, Peña de Bernal, 2100 m, matorral xerófilo, en nopal, 3 - III- 1999, E. García col. ” (13, MAAS). “ Ezequiel Montes, km 44 de carretera Bernal-Tolimán, 2067 m, matorral xerófilo, en nopal podrido, 2 - III- 1999, K. Robles y J. Márquez cols. ” (2, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776E7F4181AFA522FC0AFAE9.taxon	description	Figs. 6 a, 11 g, 15 – o, 19 – l, 23 i, 27 b Total body length 8.4 mm. Black on head, mandibles, pronotum, scutellum and mesoventrite. Antennae almost black, with some irregular parts brown. Maxillary and labial palpi reddish-brown. Prosternum black with some parts brown. Elytra, legs and abdomen reddish-brown, with elytra shinier than remaining body. Head: slightly transverse (ratio 0.86) and dorsally slightly convex. Dorsal surface with sparse punctures, about ten in each half, distributed as in majority of species; sulcate longitudinal midline weakly visible in anterior half of head; front slightly foveate between antennal insertions. Posterior corners with some setae and roughness, remotely resembling a temporal carina. Eyes small, 0.38 times the cephalic lateral length, weakly protruding laterally. Antennomeres 4 – 6 elongate, 7 – 10 almost as long as wide. Mandibles slightly shorter than head (ratio 0.92), with two teeth (basal and middle) well separated between them, middle tooth of right mandible the longest; mandibular channel with external margin expanded at base and widely separated from internal margin for almost all its length, internal margin carinate and extending to level of middle tooth, where follows forward like impressed line. Ventral surface of head with sparse, fine punctures at posterior corners. Head 1.2 times wider than pronotum. Thorax: pronotum with five punctures in each dorsal row, irregularly aligned and spaced; pronotum slightly longer than wide (ratio 1.17) and slightly wider at anterior corners than at posterior corners (ratio 1.1). Scutellum black, with microsculpture like wavy lines and punctures denser than on elytra, but concentrated at center. Elytra shiny, with punctures somewhat sparse, with remarkable yellowish setae. Prosternum elevated near anterior margin and separated from middle and posterior area (that also are elevated) by a faint constriction. Intercoxal process of mesoventrite narrowly triangular, with apex acute; transverse discal ridge well defined, broadly V-shaped, meeting margin of intercoxal process laterally (Fig. 11 g). Middle and posterior legs long and slender. Profemur with external row formed by nine to ten spines that initiate almost at mid length and end before apex, last external spine not reaching level of six or seven apical spines of internal side of femur; spines reddish, longest spines of external margin as long as spines of protibiae. Males and females with middle and posterior legs without modifications. Tarsomeres elongate, metatarsus slightly shorter to almost as long as metatibiae; only the last tarsomere is slightly flattened dorsally. Tarsal claws longer, almost as long as second tarsomere. Abdomen: visible tergites 1 – 2 with posterior basal transverse carina complete and very closer to anterior margin, tergite 3 with posterior basal transverse carina incomplete, only clearly visible at sides; adjacent area moderately depressed and wide, with punctures slightly wide combined with dense, fine punctures, that cover also remaining surface of these tergites as well as tergites 5 – 6; tergite 4 with anterior half with some wide punctures combined with fine punctures and posterior half only with fine punctures. Sternites with similar punctures as on tergites, but wide punctures slightly denser. Male pregenital sternite weakly emarginate at posterior margin (Fig. 15 – o). Male genital sternite moderately elongate (2.58 times longer than wide), very asymmetrical, anterior portion occupying 20 % and posterior portion 80 % of its length, apical emargination moderately deep (Fig. 19 – l). Abdominal styli slender. Aedeagus: length 1.1 mm; cone-shaped, sides not gradually but slightly angulately narrowed towards apex; apex subacute; basal half wider than apical half, although this gradually becomes narrower; internal sac visible (Fig. 23 i). Variability. Total body length in males 9.1 mm (range 8.5 – 10.0 mm), in females 9.3 mm (range 9.2 – 9.4 mm); ratio length / width of head in both sexes 0.88 (range 0.88 – 0.89); ratio mandibular length / cephalic length in males and in females 0.96 (range 0.92 – 1.00); head in males 1.15 times wider than pronotum (range 1.14 – 1.17), in females 1.11 (range 1.11 – 1.12); ratio length / width of pronotum in males 1.17 (range 1.16 – 1.17), in females 1.18 (range 1.16 – 1.20); ratio anterior width / posterior width of pronotum in males 1.10 (range 1.10 – 1.11), in females 1.08 (range 1.07 – 1.09). The color of antennae and prosternum is black with some irregular brown parts, the apical half of mandibles can be reddish and metaventrite can be reddish-brown. In females there are six punctures in one of the two dorsal rows of pronotum and five in the second row. Taxonomic comments. This species can be confused with B. rufiventris and it is distinguished from this species by having five or six punctures in each dorsal row of pronotum, small eyes (0.38 times the cephalic lateral length), reddish coxae, elytra and abdomen with dense fine setae, third visible abdominal tergite with posterior basal transverse carina inclomplete, male pregenital sternite moderately emarginate at posterior margin, and aedeagus 1.1 mm of length, with apex moderately acute, and sides narrowed apicad with a slight angle (Fig. 23 i). Conversely, B. rufiventris has only two punctures in each dorsal row of pronotum, eyes slightly longer than 0.5 times the cephalic lateral length, coxae black or dark-brown, elytra and abdomen with fine and sparse setae, third visible abdominal tergite with posterior basal transverse carina well developed, male pregenital sternite deeply emarginate at posterior margin and aedeagus 1.3 mm of length, with a faint contriction near base, apex very acute, and sides converging in almost straight line toward acute apex (Fig. 24 a). It is worth mentioning that the four studied specimens of B. longitarsus were in bad condition, possibly due to the fact that they were collected dead in a rodent nest. The long legs and claws (especially the tarsomeres), and its similarity to B. rufiventris (which has also been collected in gophers’ nests), suggests that this species may be a specialized associate of rodent nests.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776E7F4181AFA522FC0AFAE9.taxon	etymology	Etymology. The name of this species is derived from a combination of the words “ longus ” and “ tarsus ”, and refers to the very long tarsi, although it is not the only species with this character.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776E7F4181AFA522FC0AFAE9.taxon	materials_examined	Type material (two males, two female): Holotype (male, IEXA): “ México: Veracruz, Perote, Frijol Colorado, 2420 m, en nido de roedor, 6 - VI- 2015, E. Mora y L. Delgado cols. ” The holotype lacks the last eight antennomeres of right antenna, the apical antennomere of left antenna, and in the right middle leg, lacks the tibia and tarsomeres. Paratypes: same data as holotype (m 1, f 1, IEXA; f 1, CC-UAEH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776D7F4081AFA36FFEB0FAB1.taxon	description	Figs. 6 b, 17 d, 19 m, 24 a, 27 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776D7F4081AFA36FFEB0FAB1.taxon	description	Head: dorsally slightly convex, with rounded posterior corners and quadrate shape toward front; ratio length / width in males 0.84 and 0.85, in females 0.92 and 0.96. Dorsal surface with sulcate longitudinal midline slightly visible only at front; front weakly foveate. Eyes slightly longer than 0.5 times the cephalic lateral length, weakly protruding at sides. First antenommere as long as antennomeres 2 – 3 combined, antennomeres 2 – 3 of almost same length, 4 – 5 slightly longer than wide, 6 as long as wide, 7 – 10 transverse. Mandibles as long as head (ratio in males 1.00 and 1.03, in females 0.69, in the second female the mandibles are closed); mandibles in males moderately expanded at base, with a basal tooth and smaller middle tooth that are well separated; mandibular channel with external margin carinate and internal margin like carinate line strongly developed until level of middle tooth, then it fades toward apex. Apical palpomere of maxillary and labial palpi near 1.25 times longer than preapical palpomere. Ratio cephalic width / pronotal width in males 1.18 and 1.22, in females 1.04 and 1.25. Neck with wrinkled microsculpture ventrally. Thorax: pronotum with microsculpture like wavy lines moderately visible; ratio length / width of pronotum in males 1.11 and 1.15, in females 1.10 and 1.23; ratio anterior width / posterior width of pronotum in males 1.08 (both specimens), in females 1.04 and 1.11; dorsal rows each with only two punctures, with anterior punctures placed at anterior margin and posterior puncture placed at level of lateral macroseta. Elytra and scutellum with fine, moderately dense punctation, covered with pale setae. Prosternum with area near to anterior margin slightly elevated. Intercoxal process of mesoventrite V-shaped; transverse discal ridge well defined, broadly U-shaped or V-shaped, not meeting margin of intercoxal process laterally. Profemur somewhat flattened, in basal 3 / 4 of its length with only external margin with row of spines, in apical quarter is separated in external and internal margins; spines on external margin numerous and reddish and only some apical spines at internal margin. Posterior legs without modifications in both sexes. Legs generally very long in respect to body and with few spines on tibiae. Femora of all legs more flattened than in majority of species. Tarsomeres weakly flattened dorsally, very long, tarsomeres of posterior legs longer than posterior tibiae. Abdomen: first three visible tergites with posterior basal transverse carina moderately developed; without depressed adjacent zone, punctures very similar in shape (fine) and density (moderate) over entire surface of each tergite. Abdominal sternites with similar setae as on tergites. Male pregenital sternite deeply emarginate at posterior margin (Fig. 17 d). Male genital sternite moderately elongate (2.77 times longer than wide), moderately asymmetrical, anterior portion occupying 36 % and posterior portion 64 % of its length, apical emargination deep (Fig. 19 m). Abdominal styli slender. Aedeagus: length 1.3 mm; cone shaped, with a faint constriction near base; sides converging in almost straight line to form the acute apex; basal half notably wider than apical half, mainly in lateral view; internal sac slightly visible (Fig. 24 a). Variability. In addition to the variation in the measurements and ratios indicated in the description, one female has slightly darker coxae, its mandibles are shorter than the head, and the shape of head is more oval. Part of the sulcate longitudinal midline of head is faintly seen on the front of the second female. Taxonomic comments. Its greatest similarity is with B. longitarsus (see taxonomic comments of that species). The female holotype of this species was not studied, but we analyzed some photos of this specimen (NHM, shared by M. Chani Posse, also a photo included in the work of Chani-Posse et al. 2018 b), which together with the information of the original description (Sharp 1887) allowed us to identify this species. It is possible that the type locality of this species, “ Amecameca in Morelos ” (Sharp 1887: 787) could be placed in the Estado de México, like in one of the studied specimens.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776D7F4081AFA36FFEB0FAB1.taxon	materials_examined	Material examined (two males, two females): Mexico: Estado de México: “ Amecameca, 16 - IX- 1964, ex nest of / Cratogeomys merriami merriami, G. Halffter & E. G. Matthews, Field Museum ” (m 2, f 1, FMNH). Morelos: “ Mexicapa, bosque de pino, zona 3, NTP- 80 (calamar), 14 - VIII- 1993, A. Soria, C. Cabello y E. Córdoba cols. ” (f 1, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776C7F4581AFA39AFA03FAE4.taxon	description	Figs. 6 c – e, 16 m, 19 n, 24 b, 32 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776C7F4581AFA39AFA03FAE4.taxon	description	Head: transverse; ratio length / width in males 0.82 (range 0.75 – 0.91), in females 0.89 (range 0.85 – 0.94). Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front moderately foveate between antennal insertions. Eyes slightly less than 0.5 times the cephalic lateral length, slightly protruding laterally. Antennomere 4 elongate, 5 as long as wide, 6 – 10 transverse. Ratio mandibular length / cephalic length in males 1.11 (range 0.95 – 1.32), in females 0.84 (range 0.78 – 0.89); males with mandibles notably expanded at base, each with two clearly separated teeth, middle tooth slightly longer than basal tooth; mandibular channel well developed, with external margin clearly visible, internal margin carinate at base, extending forwards like impressed line beyond of level of middle tooth. Apical palpomere of maxillary and labial palpi longer than 1.25 times, but less than 1.5 times, the preapical palpomere. Ratio cephalic width / pronotal width in males 1.18 (range 1.10 – 1.27), in females 1.06 (range 1.02 – 1.09). Thorax: each dorsal row of pronotum with five punctures; ratio length / width of pronotum in males 1.14 (range 1.07 – 1.19), in females 1.19 (range 1.16 – 1.23); ratio anterior width / posterior width of pronotum in males 1.09 (range 1.05 – 1.14), in females 1.06 (range 1.03 – 1.09). Scutellum with punctures slightly denser than on elytra, where are moderately dense. Prosternum transversally carinate next to anterior margin and delimited blackwards by an indistinct impressed line. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly V-shaped, meeting margin of intercoxal process laterally. Profemur of males without discernible internal margin, only near apex with five to six aligned, moderately large spines; external margin with row of spines only in anterior third and not extending until apex, spines at center of row bigger than spines at sides, and also bigger than apical spines of internal margin. Posterior legs of males and females without modifications. Tarsomeres flattened dorsally. Abdomen: visible tergites 1 – 3 with posterior basal transverse carina well developed; adjacent area moderadately depressed, with dense wide-superficial punctures, combined with fine punctures; density of wide-superficial punctures decreasing toward apex in tergites 1 – 3; visible tergite 4 with punctures as on previous tergites; visible tergites 5 – 6 only with fine punctures. Visible sternites 1 – 3 with wide-superficial punctures combined with fine punctures on entire surface; visible sternites 4 – 5 with wide-superficial punctures decreasing in density toward apex; parts of 5 – 6 visible sternites with fine punctures. Male pregenital sternite moderately emarginate, emargination broadly rounded (Fig. 16 m). Male genital sternite short (2.42 times longer than wide), very asymmetrical, anterior portion occupying 32 % and posterior portion 68 % of its length, apical emargination moderately deep (Fig. 19 n). Abdominal styli slender. Aedeagus: length 1.0 mm; cone shaped, although narrower at base than previous species of this group; apex very acute; basal half moderately wider than apical half, but in lateral view, basal half is notably wider than apical half; internal sac visible (Fig. 24 b). Variability. In addition to the variation in measurements and ratios indicated in the description, and those related to sex and size of specimens, it was noted that the sulcate longitudinal midline of head is more distinct behind the middle of head and the apical antennomere may be paler than the previous ones. The main variation is in the color of ventral part of the thorax, which can be reddish, brown, dark brown or black in some parts; only in the analyzed syntypes of B. iteratus the entire ventral part of thorax is reddish (the specimens are possibly teneral), in the rest of specimens at least the central areas of the sterna always appear darker than at sides, although there are no clear limits, but both colors are mixed (reddish with dark); at most, the complete sterna and even part of legs (coxae, trochanters and femora) are blacker or darker brown, although the legs do not become darker than brown. The fifth visible abdominal segment generally has less than 1 / 4 anterior reddish and the rest black, but in some specimens this segment can be almost all black (although it can merely appear this way due to a more contracted abdomen) and the reddish part is never larger than 1 / 4 of the segment length. Taxonomic comments. Four syntypes of Philonthus iteratus deposited in the NHM (three males and one female), which are possibly teneral (or are a variation in the light color of the sterna of the thorax), were reviewed. They are the only ones with a reddish sternum, devoid of dark to black spots described in the variability. Furthermore, the male specimen glued to a plate along with a female specimen, which includes the handwritten word “ type, ” is the only one with six punctures in each dorsal row of the pronotum instead of five as is characteristic of B. xanthomelas. Despite these differences, it is proposed that P. iteratus is a junior synonym of B. xanthomelas because their main diagnostic structures are the same, such as the shape and size of the aedeagus, the male genital and pregenital sternites, the mandibles expanded at base, the very long and numerous spines in the anterior tibiae of the males, the first three visible abdominal tergites with few wide superficial punctures limited to the weak depressions and generally the same pattern of body coloration. Belonuchus xanthomelas could be confused with B. basiventris, and the characters that distinguish them have been provided in the taxonomic comments of the latter species. The type material of B. xanthomelas was not studied, but the information in the original description (Solsky 1868), Sharp’s additional information (1885) and the congruent identification of diagnostic characters between our studied specimens and some photos (Fig. 6 d; NHM, shared by M. Chani Posse) of specimens analyzed by Sharp (1885) in the Biologia Centrali Americana were considered sufficient to ensure the correct identification of this species, as well as the synonymy here proposed.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776C7F4581AFA39AFA03FAE4.taxon	materials_examined	Type material examined from B. iteratus (three males, one female): Lectotype (male, NHM) and one paralectotype (female, NHM) glued in the same plaque: “ Philonthus iteratus Type D. S. Villa Lerdo, Durango, Höge / Villa Lerdo, Durango, Höge / B. C. A. I. 2. Philonthus iteratus, Sharp / Sharp Coll. 1905 - 313 / Belonuchus iteratus (Sharp, 1885) det. Chani Posse et al. 2018 / Lectotype Philonthus iteratus Sharp, 1887, Márquez & Asiain des. 2022 ”. Paralectotypes: “ Villa Lerdo, Durango, Höge / Philonthus iteratus, Sharp / Sharp Coll. 1905 - 313 ” (m 2, NHM). Additional material examined of B. xanthomelas (18 males, 21 females): Mexico: Baja California Norte: “ Ensenada, 1 - VI- 34 / Collection of H. Leech ” (11, FMNH). Hidalgo: Singuilucan, Matías Rodríguez, N 20 ° 3.734 ’, W 98 ° 33.136 ’, 2740 m, bosque de pino-encino, en troncos con hongos, 8 - IV- 2007, J. Asiain y J. Márquez cols. ” (1, CC-UAEH). “ Singuilucan, Los Mirasoles, N 19 ° 59.460 ’, W 98 ° 29.460 ’, 2620 m, bosque de pino-encino perturbado, en maguey podrido, 22 - X- 2002, J. Asiain y J. Márquez cols. ” (1, CC-UAEH). “ Zempoala, Mina de San Juan Tepemazalco, N 19 ° 54 ’, W 98 ° 43 ’, 2600 m, bosque de encino, en nopales podridos, 10 - IX- 2002, J. Márquez col. ” (1, CC-UAEH). Michoacán: “ 2 km S de Patzcuaro, bosque de pino perturbado (eucaliptos), 2050 m, en maguey podrido, 21 - IX- 2001, J. Márquez col. ” (5, MAAS). Morelos: “ Mexicapa, bosque de pino, NTP- 80 (calamar), zona 2, 25 - IV- 1993, A. Soria, C. Cabello y E. Córdoba cols. ” (1, MAAS). “ Tlayacapan y Tlalnepantla camino a San José de los Laureles, cultivo temporal, en nopales podridos, 15 - VIII- 1998, R. Toledo y J. Márquez cols. ” (2, MAAS). “ Tlayacapan, San José de los Laureles, localidad 3, bosque mesófilo de montaña perturbado, NTP- 80, II- 1996, J. Márquez col. ” (2, MAAS). Same data, except: “ localidad 1, bosque de pino-encino, III- 1996, K. Villavicencio y J. Márquez cols. ” (2, MAAS). Same data, except: “ localidad 3, bosque mesófilo de montaña perturbado, J. Márquez col. ” (3, MAAS). “ Tlayacapan, San José de los Laureles, localidad 2, bosque pino, NTP- 80, IV- 1995, K. Villavicencio y J. Márquez cols. ” (1, MAAS). Same data, except: “ II- 1996, J. Márquez col. ” (1, MAAS). Same data, except: “ I- 1996, J. Márquez col. ” (1, MAAS). “ Tlayacapan, San José de los Laureles, bosque mesófilo de montaña, localidad 3, 15 - VIII- 1998, en troncos caídos, R. Toledo y J. Márquez cols. ” (1, MAAS). “ Tlayacapan, Santa Catarina, selva baja caducifolia y huertos, en hojarasca, 16 - VIII- 1998, J. Márquez y R. Toledo cols. ” (1, MAAS). Veracruz: “ Las Vigas, Reserva Ecológica San Juan del Monte, N 19 ° 36 ’ 53 ”, W 97 ° 06 ’ 27 ”, bosque de pino, 2449 m, en maguey podrido, 11 - VIII- 2000, Q. Santiago, J. Márquez y J. Asiain cols. ” (3, MAAS). Same data, except: “ 15 - IV- 1999 ” (1, MAAS). United States: Texas: “ Jeff Davis Co., Fort Davis, NW Limpia Canyon, 1 - VIII- 1969 / FMHD # 69 - 3007, edge of campground area, bait trap, W. S. Suter ” (m 1, FMNH). Group 4: ephippiatus This group is established for B. ephippiatus (Say, 1830) (Fig. 6 f) and B. moroni Márquez, Asiain & Navarrete-Heredia, 2018 (Fig. 6 g). These species have been recently reviewed by Márquez et al. (2018), so in this work they are only included in the proposal of species groups and in the identification key. Additionally, the diagnostic characters are given that allow easy recognition from other species or groups of species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776C7F4581AFA39AFA03FAE4.taxon	diagnosis	Diagnosis of the ephippiatus group: head oval and widened posteriad (Figs. 6 f, g); without temporal carina; eyes very small, clearly less than 0.5 times the cephalic lateral length; antennomeres 5 – 10 clearly transverse and bigger than apical antennomere; mandibles not expanded at base but with striations, basal tooth not discernible, left mandible with two middle teeth very close to each other forming a cavity like a C, right mandible with only one middle tooth; intercoxal process of mesoventrite (Fig. 11 h) strongly converging apically to form an acute and slightly raised apex; transverse discal ridge weakly developed toward sides and well developed at center, where has an apex similar to that of intercoxal process; with a short longitudinal carina near to anterior margin (similar to that of B. cariniventris); profemur with two rows of spines, both males and females, with a similar arrangement as on metafemur (Fig. 13 g), space between rows of spines of metafemur with conspicuous microsculpture like wavy lines; tarsomeres of all legs robust and with a median longitudinal groove dorsally (Fig. 13 – l); visible abdominal tergites 1 – 3 with posterior basal transverse carina well developed, visible tergite 4 also with posterior basal transverse carina, although can be incomplete at center; visible tergites 1 – 5 with coarse meshed microsculpture in anterior third contrasting with remainder of its surface, where it is like wavy lines; visible abdominal sternites 1 – 5 with similar pattern of microsculpture as on tergites, but covering almost half of its length; with coarse setae on abdominal segments; aedeagus with reduced paramere that is placed slightly basad midlength of aedeagus, apex subacute (Figs. 24 c, d).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776C7F4581AFA39AFA03FAE4.taxon	description	Included species: B. cifuentesi Rodríguez & Navarrete-Heredia, 2016, B. dichrous Erichson, 1840, and B. flavipennis Solsky, 1870.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789776C7F4581AFA39AFA03FAE4.taxon	diagnosis	Diagnosis of the arizonicus group: head with temporal carina (Figs. 9 d – e); mandibles not expanded at base, shorter than head in both sexes (Figs. 7 a, c, e); pronotum with variable number of punctures in each dorsal row, generally less than five; metatrochanters in both sexes without modifications; metafemora in both sexes with two rows of spines; tarsomeres rather robust and flattened dorsally; color body variable; aedeagus with fused paramere, well-developed, slender and long (Figs. 24 e – g).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977697F4481AFA36FFCB2FE49.taxon	description	Figs. 7 a, 20 a, 24 e, 32 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977697F4481AFA36FFCB2FE49.taxon	description	Taxonomic comments. This species can be confused with B. dichrous and B. flavipennis. The means of separation from B. dichrous is mentioned in the taxonomic comments of that species. Belonuchus cifuentesi is distinguished from B. flavipennis by having the legs and first two visible abdominal segments reddish as elytra, male genital sternite very elongate (3.28 times longer than wide), aedeagus large (3.1 mm), oval-elongate shape, with apex subacute (Fig. 24 e). While B. flavipennis has legs and all abdomen black, except anterior border of sixth visible segment, male genital sternite short (2.21 times longer than wide), small aedeagus (1.13 mm), with elongate shape, convex apex, slightly acute in ventral view and moderately acute in lateral view (Fig. 24 g). Belonuchus cifuentesi also can be confused with B. arizonicus. According with Rodríguez & Navarrete-Heredia (2016: 450), “ B. cifuentesi is recognized by the black abdominal segments from tergite V, the pleurites VI and VIII are black in more than half of specimens, antennomeres pubescent, tempora less than twice as long as the length of the eyes, the first 4 antennomeres are longer than width, anterior corners and pronotal hypomera reddish-brown, frons with wide fovea and with a longitudinal impression, dorsal surface with scattered umbilicate punctures, first three antennomeres bearing only sparse strong setae, outer antennomeres (4 – 11) with microtrichia and long setae, profemur with two lines of spines of irregular size, metafemur with two lines of small and strong spines; tibiae with several spines; tarsi filiform, first and fifth tarsomeres longer than each one of the second to fourth, aedeagus small, narrow and elongate, median lobe subparallel-sided to slightly, evenly narrowed toward obtuse apex and smaller than B. arizonicus (Fig. 9) ”.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977697F4481AFA36FFCB2FE49.taxon	materials_examined	Type material examined (two males): Paratypes: “ México: Jalisco, Teocuitatlán de Corona, Cerro de García, colecta manual en Agave inaequidens, 2 - VII al 3 - VIII de 2014, 20 ° 09´N, 103 ° 19´W, 2314 msnm, col. William D. Rodríguez / Paratype Belonuchus cifuentesi Rodríguez & Navarrete-Heredia (2015) ” (m 1, CEZUG). Same data as previous, except: “ 3 - VIII al 3 - IX de 2014 ” (m 1, CEZUG).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977687F4B81AFA7CFFD30F8A9.taxon	description	Figs. 7 b, c, 9 d, e, 11 i, 16 b, 20 b, 24 f, 32 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977687F4B81AFA7CFFD30F8A9.taxon	description	Head: slightly transverse, ratio length / width in males 0.92 (range 0.91 – 0.95), in females 0.90 (range 0.88 – 0.92), sides and posterior corners somewhat convex; with well developed, oblique temporal carina from dorsal to ventral surface (Figs. 9 d – e). Dorsal surface with punctures distributed as in majority of species, but less dense; sulcate longitudinal midline visible in anterior half of head; front little to moderately foveate between antennal insertions. Eyes small, 0.4 times the cephalic lateral length, not protruding at sides. Antennomere 4 elongate, 5 – 10 transverse. Mandibles shorter than head (ratio in males 0.76, range 0.71 – 0.79; in females 0.73, range 0.68 – 0.79); with microsculpture like wavy lines near its base, left mandible with two middle teeth very close to each other (similar as in B. ephippiatu s), right mandible with a middle tooth and in some specimens with another very small tooth beneath first; both mandibles without visible basal tooth; mandibular channel moderately developed, with external margin not carinate and internal margin carinate, extending forward near level of most apical tooth and then is lost. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Ventral surface of head with very fine and sparse punctures. Head wider than pronotum (ratio in males 1.21, range 1.17 – 1.26; in females 1.18, range 1.15 – 1.22). Thorax: pronotum with microsculpture like wavy lines more distinct than on head; each dorsal row of pronotum with three punctures, first one very close to anterior margin and following two not exceeding beyond anterior half; sublateral punctures sparser than in majority of species; pronotum slightly longer than wide (ratio in males 1.07, range 1.03 – 1.10; in females 1.10, range 1.03 – 1.15) and wider at anterior corners than at posterior corners (ratio in males 1.21, range 1.20 – 1.23; in females 1.21, range 1.12 – 1.27). Scutellum and elytra with fine and dense punctures. Prosternum without an elevated zone near anterior margin. Intercoxal process of mesoventrite scutellum-shaped, apex acute with a small pick; transverse discal ridge notably less curved posteriad than margin of intercoxal process, slightly acute apically, meeting margin of intercoxal process laterally, with a faint midlongitudinal carina reaching until anterior margin (similar to the carina observed in B. cariniventris and B. ephippiatus) (Fig. 11 i). Profemur of both sexes with two rows of spines, external row initiating distant from its base and ending before apex, internal row developed almost on all its length; both rows with small, black spines. Metafemur in both sexes with two rows of spines well aligned on almost all its length, spines slightly separated and bigger than on profemur; internal area between both rows with conspicuous microsculpure like wavy lines. Metatibiae with black spines, which contrast with the reddish color of the tibial surface. Tarsomeres somewhat robust (not as robust as in ephippiatus group) and flattened dorsally. Abdomen: entire abdomen with very dense, large and short setae; first two visible tergites with straight posterior basal transverse carina and third tergite with zig-zagging posterior basal transverse carina or at least not straight; adjacent area narrow and weakly depressed; both tergites and sternites (especially 3 and 4), with coarse meshed microsculpture in anterior 1 / 3 to 1 / 2 of its length, then fading until there is only finer microsculpture like wavy lines (as in ephippiatus group). Visible sternites 1 – 5 with conspicuous sinuous posterior basal transverse carina. Male pregenital sternite weakly emarginate at posterior margin (Fig. 16 b). Male genital sternite moderately elongate (2.89 times longer than wide), very asymmetrical, anterior portion occupying 23 % and posterior portion 77 % of its length, apical emargination very deep (Fig. 20 b). Abdominal styli slender, with external margin slightly curved and internal margin straight. Aedeagus: length 1.2 mm; oval shape in basal half and elongate in apical half; fused paramere as long as 1 / 2 of aedeagus length; apex somewhat convex, not acute; in lateral view, apex looks slightly directed toward ventrad; in ventral view, basal half notably wider than apical half, not as evident in lateral view; internal sac not visible (Fig. 24 f). Variability. In addition to the variation indicated in the description regarding measurements and ratios, some specimens have the apical antennomere reddish and the preapical antennomere black; right mandible with the first middle tooth very small until not discernible, in the latter case only one middle tooth is visible; visible tergite 3 with posterior basal transverse carina variably developed, in part due to the coarse meshed microsculpture that covers it. Taxonomic comments. Species in the arizonicus group share several characteristics with the ephippiatus group, suggesting that they could turn out as sister groups in a future study that considers all the species of the genus. Among these characteristics are the small eyes on a somewhat robust head, mandibles shorter than head, teeth of left mandible, the arrangement of the two rows of spines at anterior and posterior tibiae of both sexes, the development of two types of microsculpture on each abdominal segment and the robust tarsomeres. The ratio of antennomeres is somewhat similar, but not the same, the coarse microsculpture at base of mandibles in B. dichrous also resembles the striated mandibles of the ephippiatus group. Belonuchus dichrous is distinguished from B. cifuentesi and B. flavipennis by having the pronotum reddish as the elytra and only the posterior border of fifth visible abdominal segment and entire sixth segment reddish. While B. cifuentesi has the pronotum black and the elytra reddish, with first two visible abdominal segments reddish and the rest black. Unlike B. dichros, B. flavipennis has only the elytra reddish and the rest of the body black (except the anterior border of sixth visible abdominal segment that is reddish). The syntypes of this species were not studied, but we consider that the information of the original description (Erichson 1840), the additional information given by Sharp (1885) and the congruent identification of diagnostic characters between the studied specimens and some photos (Fig. 7 b; NHM, shared by M. Chani Posse) of specimens depicted by Sharp (1885) in the Biologia Centrali-Americana, are sufficient to be sure of the correct identification of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977687F4B81AFA7CFFD30F8A9.taxon	materials_examined	Material examined (13 males, 15 females): Mexico: Hidalgo: “ Huehuetla, Rio Blanco, 588 m, UTM (WG- 384), 14594809 E, 2257303 N, bosque tropical perennifolio, NTP- 80 (calamar) 1 a 30 - V- 2010, C. Berriozábal col. ” (1, CC-UAEH). “ La Misión, Los Naranjos, Palo Hueco, bosque mesófilo de montaña, 1216 m, N 21 ° 08 ’ 06 ”, W 98 ° 05 ’ 02 ”, coprotrampa, del 10 al 24 - III- 2011, J. Márquez col. ” (1, CC-UAEH). “ Molango, Acuatitlán, bosque mesófilo de montaña, 1715 m, N 20 ° 45 ’ 38.4 ”, W 88 ° 42 ’ 50.7 ”, tronco podrido de colorín, 30 - IX- 2011, J. Márquez col. ” (1, CC-UAEH). “ Tepehuacán de Guerrero, Otongo, 650 m, ex carrion trap, 2 - march- 1981, M. A. Morón ” (2, IEXA). Puebla: “ Xicotepec de Juárez, Cañada de Patla, bosque mesófilo de montaña perturbado, 11 - XI- 1994, en tronco caído, J. Márquez col. ” (2, MAAS). Same data, except: “ 5 - I- 1995 ” (1, MAAS). Veracruz: “ Córdoba, Ojo de Agua, selva mediana subcaducifolia, 1127 m, en tronco caído, 23 - X- 1998, R. Toledo, G. Flores, Q. Santiago y J. Márquez cols. ” (1, MAAS). Same data, except: “ en lima podrida, 24 - I- 1999, Q. Santiago, J. Asiain y J. Márquez cols. ” (1, MAAS). “ Totutla, Mata Oscura, 1 km S de Zacuapam, selva mediana subcaducifolia, 921 m, café podrido, 16 - IV- 1999, J. Asiain, Q. Santiago y J. Márquez. ” (3, MAAS). Same data, except: “ 19 - III- 1999, J. Asiain, G. Rodríguez, Q. Santiago y J. Márquez cols. ” (1, MAAS). “ Xalapa, San Antonio Paso del Toro, N 19 ° 35´20.3 ”, W 96 ° 50´17.5 ”, 990 m, selva baja caducifolia, trampa de intercepción de vuelo # 1, 4 - IV- 2015, L. Delgado col. ” (3, IEXA). Same data, except: “ 2 - V- 2015 ” (2, IEXA). Same data, except: “ 2 a 30 - V- 2015, K. Cortés, J. Sulvaran y Q. Santiago cols. ” (2, QJSJ; 1, IEXA). Same data, except: “ 30 - V a 27 - VI- 2015 ” (1, IEXA). “ Xico, San Marcos, N 19 ° 25´6.23 ”, W 96 ° 57´58.13 ”, 1155 m, en lombricomposta de pulpa de café, 6 - V- 2015, H. Pacheco col. ” (1, QJSJ). Same data, except: “ 21 - V- 2015 ” (1, QJSJ). Same data, except: “ N 19 ° 24´25.25 ”, W 96 ° 57´31.06 ”, 1125 m ” (1, QJSJ). Same data, except: “ N 19 ° 27´56.70 ”, W 96 ° 55´57.31 ”, 1210 m ” (1, QJSJ). Same data, except: “ N 19 ° 27´56.70 ”, W 96 ° 55´57.31 ”, 1210 m, 6 - V- 2015 ” (1, QJSJ).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977667F4881AFA6ABFA03FF2E.taxon	description	Figs. 7 d, e, 11 j, 16 c, 20 c, 24 g, 29 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977667F4881AFA6ABFA03FF2E.taxon	description	Head: subquadrate, sides and posterior corners slightly convex; ratio length / width of head 0.86 (range 0.85 – 0.87). Dorsal surface with punctures slightly sparser than in majority of species; sulcate longitudinal midline visible for almost all cephalic length, although less notable in posterior half; front weakly foveate between antennal insertions. Temporal carina strongly developed from ventral to dorsal surface, ending in a big setiferous puncture. Eyes small, 0.4 times the cephalic lateral length, not protruding laterally. First antennomere almost as long as 2 – 3 combined, 3 slightly longer than 2 (1.25 times), 4 as long as wide, 5 – 10 transverse. Mandibles shorter than head (ratio 0.87, range 0.85 – 0.89); each with three teeth, basal tooth small but discernible, two middle teeth very close to each other, interspace C-shaped; base of each mandible with conspicuous mesh-like microsculpture; mandibular channel little to moderately developed, external margin not carinate but like impressed line, internal margin like impressed line that fades at level of the most apical tooth. Apical palpomere of maxillary palpi nearly 1.5 times longer than preapical palpomere; apical palpomere of labial palpi nearly 1.25 times longer than preapical palpomere. Head 1.18 times wider than pronotum (range 1.14 – 1.22). Neck, in ventral view, with three impressed lines not clearly visible and mesh-like microsculpture. Thorax: each dorsal row of pronotum with four punctures; pronotum almost as long as wide (ratio 1.03, without variation) and slightly wider at anterior corners than at posterior corners (ratio 1.135, range 1.13 – 1.14). Scutellum with punctures wider than on elytra, both with punctures moderately dense. Prosternum with the area close to anterior margin transversally elevated and delimited posteriad by an impressed line. Intercoxal process of mesoventrite shield-shaped, apex acute and slightly projected anteriad; transverse discal ridge broadly V-shaped, with irregular sides, not meeting margin of intercoxal process laterally, apex acute, beak-shaped; area delimited by anterior margin of mesoventrite and discal ridge with a longitudinal carina along its entire length (similar to ephippiatus group); entire mesoventrite with microsculpture like wavy lines; area between intercoxal process and posterior margin covered by coarser, meshed microsculpture, except near posterior margin where there is again microsculpture like wavy lines (Fig. 11 j). Profemur of males with external row of spines initiating at base and ending one third before apex, spines somewhat separated, short and black; internal row with spines initiating at base, but dissapearing after basal third and reappearing close to apex; space between row of spines with mesh-like microsculpture. Metafemur of males with two rows of spines well developed, external row from base until near apex, internal row ending slightly before; spines short, space between rows with conspicuous mesh-like microsculpture. Tarsomeres somewhat robust and flattened dorsally. Abdomen: entire abdomen with punctures moderately dense; visible tergites 1 – 3 with posterior basal transverse carina well developed, adjacent area narrow and slightly depressed, from anterior margin to end of depression with rough mesh-like microsculpure, contrasting with fine microsculpture of wavy lines that cover remaining surface; in visible tergite 4 with coarse meshed microsculpure on almost all its basal half, in tergite 5 covering basal 1 / 3 and in tergite 6 only with fine microsculpture. Visible sternites 1 – 5 with posterior basal transverse carina well separated from anterior margin, not straight, with sinuations; with two types of microsculpure as in tergites. Male pregenital sternite slightly emarginate at posterior margin, emargination broadly V-shaped (Fig. 16 c). Male genital sternite short (2.21 times longer than wide), weakly asymmetrical, anterior portion occupying 19 % and posterior portion 81 % of its length, apical emargination not deep (Fig. 20 c). Abdominal styli slender, slightly curved at their external margin. Aedeagus: length 1.13 mm; elongate shape; with fused paramere, almost as long as 1 / 2 of the aedeagus length, outline straight; apex convex, subacute in ventral view and more distinctly acute in lateral view; basal half slightly wider than apical half, although in lateral view this difference in width is more noticeable; internal sac slightly visible (Fig. 24 g). Variability. Only two male specimens were studied, their variation in measurements and ratios is presented in the redescription. In addition, it was observed that they can have the last or last two antennomeres lighter than rest of antennomeres and the longitudinal carina in the anterior part of the mesoventrite is slightly less developed in one specimen than in the second specimen. Taxonomic comments. In the taxonomic comments of B. dichrous and B. cifuentesi it was indicated how to distinguish them from B. flavipennis. Furthermore, B. flavipennis is superficially similar to B. ephippiatus, from which it is easily distinguished by the presence of a well developed temporal carina, four punctures in each dorsal row of pronotum, tarsomeres not so much widened or dorsally excavated, and aedeagus with an elongate paramere. On the other hand, B. ephippiatus lacks the temporal carina, has more than five punctures in each dorsal row of the pronotum, tarsomeres are wider and somewhat excavated dorsally, and the aedeagus has a short paramere. The female holotype of B. flavipennis was not studied, but photographs in dorsal and ventral view provided by A. Kovalev (Zoological Institute of the Russian Academy of Sciences) were available. Additionally, we analyzed some photographs (NHM; shared by M. Chani Posse) of specimens of this species studied by Sharp (1885), so we have no doubts about the correct identification of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977667F4881AFA6ABFA03FF2E.taxon	materials_examined	Material examined (two males): Mexico: Hidalgo: “ Acatlán, Loma Larga, El Llano, cultivos, matorral xerófilo y encinos, 2097 m, N 20 ° 16 ’ 13 ”, W 98 ° 28 ’ 18 ”, en nopales podridos, 20 - VII- 2010, J. Márquez col. ” (CC- UAEH). Group 6: platypterus Included species: B. aenigmaticus sp. nov., B. iridescens Solsky, 1868, B. juanmorronei sp. nov., B. nigerrimus Bernhauer, 1918, B. optatus (Sharp, 1885), and B. platypterus (Sharp, 1885).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977667F4881AFA6ABFA03FF2E.taxon	diagnosis	Diagnosis of the platypterus group: without any of the male sexual structures indicated in the previous groups, except B. aenigmaticus which has the metatrochanter acute apically; head without temporal carina; mandibles with a middle tooth and a basal tooth well separated from each other, both in dorsal position (in two species the left mandible has two middle teeth close to each other, interspace C-shaped, in addition to the basal tooth; Fig. 9 f); head shape subquadrate or transverse (ratio length / width 0.76 – 0.97; Fig. 10 d); mandibles 0.75 to 1.4 times as long as cephalic length; tarsomeres somewhat flattened dorsally; aedeagus with reduced paramere (Figs. 24 h – l, 25 a).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977647F4F81AFA72EFAF4F85D.taxon	description	Figs. 8 a, 13 h, 16 d, 20 d, 24 h, 33 a Total body length 9.2 mm. Black on head, antennae (except apical antennomere), pronotum, posterior half of prosternum, 3 / 4 of fifth visible abdominal segment, all sixth and abdominal styli. Reddish on elytra, legs, sterna (except for posterior half of prosternum), visible abdominal segments 1 – 4 and anterior 1 / 4 of 5, posterior margin of pregenital sternite, genital segment and base of styli. Mandibles and scutellum brown. Head: subquadrate, dorsally slightly convex; ratio length / width 0.9. Dorsal surface with sulcate longitudinal midline slightly visible in anterior half of head or slightly further back; front moderately foveate between antennal insertions. Eyes slightly longer than 0.5 times the cephalic lateral length and clearly protruding at sides. Antennomere 1 as long as antennomeres 2 – 3 combined, antennomere 2 slightly shorter than 3, 4 as long as wide, 5 – 10 transverse. Mandibles shorter than head (ratio 0.88); each mandible with two well separated teeth (basal and middle), both of small size; mandibular channel slightly developed, with external margin weakly carinate and internal margin well developed like impressed line, extending slightly beyond middle tooth level. Apical palpomere of maxillary and labial palpi slightly more than 1.5 times longer than preapical palpomere. Ventral surface with sparse punctures and fine setae toward posterior corners, in addition to punctures with fine setae on each side. Head 1.12 times wider than pronotum. Thorax: each dorsal row of pronotum with six punctures; pronotum 1.12 times longer than wide, almost as wide at anterior corners as at posterior corners (ratio 1.04). Scutellum darker and with denser broad punctures than on elytra, latter fine moderately dense punctures. Area near anterior margin slightly impressed and separated from posterior area. Intercoxal process of mesoventrite with shape intermediate between shield and scutellum; transverse discal ridge diffusely impressed, broadly U-shaped or V-shaped, not meeting margin of intercoxal process laterally. Profemur with row of spines only along external margin at middle 2 / 4 of femur length, basal spines smaller than apical spines, not more than eight to nine spines; internal margin near apex with two or three small spines. Metatrochanter with its apex ending in an inconspicuous spine (Fig. 13 h). Remainder of legs without modifications. Tarsomeres flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent area weakly depressed on tergites 1 – 2, and less so on tergite 3; depression on tergite 1 with wide-superficial punctures moderately dense in more than its anterior half, in tergites 2 – 3 this type of punctures covering nearly their anterior half; tergite 4 with sparse wide-superficial punctures and tergites 5 – 6 only with fine punctures, which are present also on previous tergites. Visible sternites 1 – 5 with posterior basal transverse carina somewhat separated from anterior margin; with punctation pattern similar to that of tergites, although slightly denser. Male pregenital sternite slightly emarginate at posterior margin (Fig. 16 d). Male genital sternite short (2.0 times longer than wide), very asymmetrical, anterior portion occupying 28 % and posterior portion 72 % of its length, apical emargination very deep (Fig. 20 d). Abdominal styli slender. Aedeagus: length 1.4 mm; cone shaped; apex moderately acute; apical half narrowing gradually toward apex, basal half ovoid and wider than apical half; internal sac conspicuous (Fig. 24 h). Variability. Total body length in males 8.81 mm (range 8.1 – 9.6 mm), in females 9.4 mm (range 8.7 – 10.5); ratio length / width of head in males 0.86 (range 0.83 – 0.88), in females 0.89 (range 0.85 – 0.96); ratio mandibular length / cephalic length in males 0.87 (range 0.85 – 0.92), in females 0.87 (range 0.81 – 0.92); ratio cephalic width / pronotal width in males 1.13 (range 1.05 – 1.19), in females 1.09 (range 1.07 – 1.13); ratio length / width of pronotum in males 1.14 (range 1.11 – 1.22), in females 1.18 (range 1.12 – 1.25); ratio anterior width / posterior width of pronotum in males 1.05 (range 1.03 – 1.09), in females 1.04 (range 1.04 – 1.05). Furthermore, the apical or apical and sub-apical antennomeres may be reddish; dorsal rows of pronotum with great variability in number of punctures: 5: 5, 6: 5, 5: 6, 6: 6, 7: 6, 7: 7. Scutellum is reddish or brown in most specimens, but in some it may be almost black. Prosternum may have reddish anterior half and black posterior half or entirely reddish. Transverse discal ridge on anterior half of mesoventrite may be better developed in some specimens. The outer row of spines on the profemur can be difficult to distinguish. Metatrochanters of males may have their apex like a very small spine or it may not end in a spine as in females. Taxonomic comments. This species is very similar to B. optatus in the following terms: overall length, coloration pattern, the few spines at the anterior tibiae in males, the posterior trochanters only spine-shaped at apex, and a similar size and shape of both the genital sternite and aedeagus. Belonuchus aenigmaticus, however, has fewer punctures on the dorsal surface of the head, mainly towards posterior corners, there are five to seven punctures in each dorsal row of the pronotum, which do not extend below three quarters of the pronotal length, the scutellum is reddish (with some variation to dark), the male pregenital sternite is slightly emarginate at the posterior margin, and its aedeagus is slightly larger, with the apex less acute and the internal sac more conspicuous. In B. optatus, there are more punctures on the dorsal surface of the head, and there are seven to nine punctures in each dorsal row of the pronotum that extend very close to posterior margin. In addition, the scutellum is black, the male pregenital sternite is slightly emarginate in posterior margin and the aedeagus is smaller, with a more acute apex and the hardly visible internal sac. On the other hand, B. aenigmaticus can be confused with B. rufipennis because of its similar body length and coloration pattern. Belonuchus aenigmaticus differs from B. rufipennis in the reddish scutellum, the lack of spines on the male metafemur, row of spines on profemur formed by few small spines, and differences in the genital sternite and aedeagus. In B. rufipennis the scutellum is black or almost black, males have two rows of spines on the posterior femora, with the spines on the external row of anterior femurs being larger and more numerous, and their genital sternite and aedeagus are different. Additionally, B. aenigmaticus can be confused with B. moquinus Casey, 1884, from the southern United States of America because both species have a similar body color, and males lack the two aligned rows of spines on the posterior femora (Smetana 1995). Even the aedeagus is somewhat similar, but the median lobe is different in B. moquinus, with a long, thin and sharp apex in both the ventral and lateral view. Furthermore, the genital sternite is elongate, with apical emargination short and V-shaped, and the scutellum is darker than the elytra. Belonuchus aenigmaticus has a reddish scutellum, almost similar to the color of elytra, the genital sternite is short, with very deep apical sinuation, and the aedeagus is cone-shaped, its apex is moderately acute, with the apical half gradually narrowing toward apex, and the basal half is oval and wider than the apical half. In the taxonomic comments of B. zunilensis some arguments are included that motivated the inclusion of this species in the platypterus group and not in the trochanterinus group.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977647F4F81AFA72EFAF4F85D.taxon	etymology	Etymology. The name of this species is derived from the word “ aenigma ” and refers to the fact that its correct placement into the species group platypterus or trochanterinus is an enigma (see taxonomic comments), as well as its great similarity with B. optatus, B. rufipennis and B. moquinus.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977647F4F81AFA72EFAF4F85D.taxon	materials_examined	Type material (10 males, eight females): Holotype (male, CC-UAEH): “ México: Hidalgo, La Misión, Las Pilas, N 21 ° 7 ’ 8.1 ”, W 99 ° 7 ’ 26.1 ”, bosque mesófilo de montaña, trampa de intercepción de vuelo, 12 a 19 - VII- 2018, J. Márquez y A. Lora cols. ”. Paratypes: Mexico: Hidalgo: “ Chapulhuacán, Puerto del Zopilote, bosque mesófilo de montaña, 1134 m, N 21 ° 09.9 ’ 7.9 ”, W 98 ° 55.8 ’ 04.0 ”, NTP- 80 (calamar) # 4, 28 - VIII a 11 - IX- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 8 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (1, CC-UAEH). “ Chapulhuacán, Tamaulipas, bosque mesófilo de montaña, 1134 m, N 21 ° 09.9 ’ 7.9 ”, W 98 ° 55.8 ’ 04.0 ”, NTP- 80 (calamar) # 1, 12 a 26 - III- 2011. J. Márquez col. ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 2 ” (1, CC-UAEH). Same data, except: “ NTP- 80 (calamar) # 3 ” (1, CC-UAEH). “ Jacala de Ledezma, P. N. Los Mármoles, camino a Plomosas, bosque de pino-encino, 1793 m, N 20 ° 57 ’ 36 ”, W 99 ° 13 ’ 2.5 ”, en hongo, 11 - X- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (1, CC-UAEH). “ Molango, Acuatitlán, bosque mesófilo de montaña, 1715 m, N 20 ° 45 ’ 38.4 ”, W 88 ° 42 ’ 50.7 ”, NTP- 80 (calamar) # 8, 15 a 29 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). “ Pacula, camino al Membrillar del Fraile, río Moctezuma, N 99 ° 23´28 ”, W 21 ° 5´26.8 ”, 903 m, vegetación riparia, NTP- 80 (calamar), 20 - I a 25 - II- 2010, J. Islas col. ” (1, CC-UAEH). “ Tlanchinol, camino a Apantlazol, El Pozo, bosque mesófilo de montaña, 1391 m, N 20 ° 59 ’ 6.73 ”, W 98 ° 37 ’ 39.86 ”, NTP- 80 (calamar) # 8, 1 a 22 - X- 2011, J. Márquez col. ” (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Minas Viejas, bosque de encino, 1892 m, N 20 ° 55 ’ 5.2 ”, W 99 ° 12 ’ 41.1 ”, NTP- 80 (calamar), del 11 - X al 17 - XI- 2007, J. Márquez, J. Asiain y S. Sierra cols. ” (4, CC-UAEH). Same data, except: “ 13 - VII al 18 - VIII- 2007 ” (1, CC-UAEH). “ Zimapán, P. N. Los Mármoles, Trancas, bosque de encino, 2444 m, N 20 ° 48 ’ 12.2 ”, W 99 ° 14 ’ 41 ”, NTP- 80 (calamar), 13 - X a 17 - XI- 2007, J. Asiain, S. Sierra y J. Márquez cols. ” (1, CC-UAEH). Same data, except: “ coprotrampa, 22 - VI al 12 - VII- 2007 ” (1, CC-UAEH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977627F4D81AFA6ABFE53FE49.taxon	description	Figs. 7 f, g, 11 m, 13 i, 15 e, 20 e, 24 i, 32 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977627F4D81AFA6ABFE53FE49.taxon	description	Head: subquadrate, ratio length / width 0.91. Sulcate longitudinal midline slightly visible in less than anterior half of head; front weakly foveate. Eyes small, 0.41 times the cephalic lateral length, slightly protruding laterally. First antennomere almost as long as antennomeres 2 – 3 combined, 2 slightly shorter than 3, 4 slightly elongate, 5 as long as wide, 6 – 10 transverse. Mandibles shorter than head (ratio 0.76), left mandible with two middle teeth very close to each other and right mandible with one middle tooth, without basal tooth; mandibular channel slightly developed, external margin slightly defined, internal margin like very fine carinate line extending forwards beyond level of most apical tooth. Apical palpomere of maxillary and labial palpi slightly more than 1.5 times longer than preapical palpomere. Head 1.27 times wider than pronotum. Ventral surface with very fine and sparse punctures. Thorax: pronotum with five punctures in each dorsal row; 1.1 times longer than wide; 1.1 times wider at anterior corners than at posterior corners. Scutellum with punctures slightly wider than, and almost as dense as on elytra, where punctures are fine and moderately dense. Prosternum without any evident elevation near anterior margin. Intercoxal process of mesoventrite scutellum-shaped, somewhat projected downwards; transverse discal ridge crenulate, not meeting margin of intercoxal process laterally (Fig. 11 m). Protibia without aligned spines at external margin, only with two to four moderately large spines near apex. Tibiae of all legs with black spines contrasting with the reddish color of legs. Posterior legs without modifications (Fig. 13 i). Tarsomeres flattened dorsally. Abdomen: visible tergites 1 – 3 with posterior basal transverse carina well developed; adjacent area weakly depressed (tergites 1 – 2) to almost flat (tergite 3), narrow, with sparse wide-superficial punctures combined with fine punctures that are moderately dense; outside depressions and remaining tergites only with dense, fine punctures; visible tergites 3 – 5 with anterior part (1 / 3 to 1 / 4) with mesh-like microsculpture, which is different than microsculpure like wavy lines on their remaining surface. Visible sternites 1 – 3 with posterior basal transverse carina, which is not visible in sternites 4 – 6; all sternites covered with dense, fine punctures; microsculpture as on tergites. Male pregenital sternite only slightly emarginate medio-apically (Fig. 15 e). Male genital sternite very elongate (3.41 times longer than wide), weakly asymmetrical, anterior portion occupying 56 % and posterior portion 44 % of its length, apical emargination deep (Fig. 20 e). Abdominal styli slender. Aedeagus: small, length 0.85 mm; elongate shape, apex very narrow and slightly curved backward; basal half slightly wider than apical half; internal sac slightly visible (Fig. 24 i). Variability. Unknown, only one male specimen was studied. Taxonomic comments. Belonuchus iridescens is easily distinguished from the rest of species of the platypterus group by its coloration pattern (first three antennomeres, pronotum, first two visible abdominal segments, sixth and genital segment reddish to yellowish), its small size (close to 7 mm) and the black spines of tibiae that contrast with the reddish color of legs (Fig. 7 g), characteristics that do not appear in any other species of this group. Information from the original description of B. iridescens and B. latecintus was compared, a photo of the holotype of the first species (provided by A. Kovalev, Zoological Institute of the Russian Academy of Sciences) and a photo of lectotype of the second species (Chani-Posse et al. 2018 b) were analyzed, as well as the study of a specimen recently collected in Oaxaca (IEXA), and it was concluded that they are the same species, so the name Philonthus latecinctus Sharp, 1885 is proposed as junior synonym of B. iridescens Solsky, 1868. The following are some relevant characters coincident in the original descriptions of B. iridescens Solsky (1868) and Philontus latecinctus Sharp (1885), which support the synonymy here proposed: total body length 5.5 – 7.0 mm; body bright reddish, head shiny, metallic-iridescent black, mandibles red, antennal apex and ante-apical segments of abdomen black, first three antennomeres red, last dark brown, pronotum shiny metallic-iridescent red, elytra testaceous-reddish, abdomen testaceous red, except segments 3 – 4 and margin of 5 that are black, prosternum red, legs red-testaceous; head quadrate; series of five dorsal punctures on the pronotum, in addition, with five punctures on margins of both sides; elytra with fine punctures, pubescence yellow (golden), dense and sub-opaque; abdomen with numerous punctures; without evident sexual dimorphism.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977627F4D81AFA6ABFE53FE49.taxon	materials_examined	Type material. The female holotype of B. iridescens Solsky was not studied, but the dorsal and ventral view were analyzed in a photograph provided by A. Kovalev (Zoological Institute of the Russian Academy of Sciences). Type material of B. latecinctus Sharp was not studied, but a photograph of the lectotype designated by Chani-Posse et al. (2018 b) was analyzed. Additional material examined (one male): Mexico: Oaxaca: “ Uluapan, 4 km NE Ayautla, N 18.05956 °, W 96.64558 °, + - 10 a 420 m, 9 a 16 - VI- 2016, M. García et al., cols. / Lowland rainforest, Malaise trap ” (m 1, IEXA).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977617F4C81AFA7C2FD16FD4C.taxon	description	Figs. 8 e, 11 – l, 16 f, 20 i, 25 a, 28 b Total body length in male 9.8 mm, in females 8.1 mm (range 7.8 – 8.4 mm). Body completely black, but legs reddish-brown in females. Head: quadrate shape, in male slightly widened posteriad; ratio length / width in male 0.97, in females 0.93 (without variation). Dorsal surface with sulcate longitudinal midline visible in anterior half of head; punctures slightly denser than in majority of species and more extensive; front moderately foveate, fovea extending backward of level of antennal insertions. Posterior corners with punctural grooves forming oblique roughness resembling a diffuse temporal carina. Eyes very small, 0.34 times the cephalic lateral length, slightly protruding laterally. Antennomere 4 almost as long as wide, 5 – 10 transverse. Mandibles shorter than head (ratio in male 0.71, in females 0.73); left mandible with two small middle teeth close to each other, interspace C-shaped; right mandible with only one middle tooth; each mandible additionally with a very small basal tooth; mandibular channel moderately developed, with external margin not carinate and internal margin like impressed line well developed that extending beyond level of most apical middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Ventral surface with sparse, fine punctures, mainly toward posterior corners; with two fine setiferous punctures placed in external anterior quarter. Head wider than pronotum (ratio in male 1.29, in females 1.20, range 1.19 – 1.22). Neck in ventral view with rough mesh-like microsculpture. Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio in male 1.15, in females 1.14, range 1.13 – 1.15) and wider at anterior corners than at posterior corners (ratio in male and females 1.14, range 1.13 – 1.15). Scutellum with punctures slightly bigger than on elytra, as dense as on elytra, where they are dense and combined with finer mesh-like microsculpture. Prosternum without modifications. Intercoxal process of mesoventrite (Fig. 11 – l) triangularly scutellum-shaped, distinctly extended posteriad, apex not very acute; transverse discal ridge well developed, broadly U-shaped or V-shaped, reaching close to margin of intercoxal process laterally. Male damaged and without anterior legs; profemur of female with four to five small spines near internal apex. Rest of legs (except tarsomeres) without modifications. Tarsomeres dorsally clearly flattened and even slightly excavated. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent zone moderately depressed; with mesh-like microsculpture, giving a rough aspect in this depression and above it; visible tergites 1 – 4 with wide-superficial punctures combined with fine punctures moderately dense near anterior margin and gradually decreasing in density toward posterior margin; visible tergites 5 – 6 with fine, sparse punctures. First visible sternite with complete posterior basal transverse carina, visible sternites 2 – 3 with incomplete posterior basal transverse carina, interrupted at sides; remaining sternites without posterior basal transverse carina; pattern of punctures on sternites similar to that of tergites, but slightly denser. Male pregenital sternite weakly emarginate at posterior margin (Fig. 16 f). Male genital sternite very elongate (3.47 times longer than wide), moderately asymmetrical, anterior portion occupying 20 % and posterior portion 80 % of its length, apical emargination deep and wide (Fig. 20 i). Abdominal styli slender. Aedeagus: length 1.0 mm; oval-elongate shape; apex acute; apical part slightly longer than 1 / 2 of aedeagus length and clearly narrower than basal part, although in lateral view this difference is not very conspicuous; internal sac visible (Fig. 25 a). Variability. The male has a small mid-ventral tooth on the right mandible that protrudes from the mid-dorsal tooth, but this was not noted in the female specimens. Little variation was noted both in measurements and ratios, as in other structures, such as brown legs of females and black legs in male. Taxonomic comments. This species can be confused with B. nigerrimus due to the black color of body, but in taxonomic comments of this species their differences have been highlighted.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977617F4C81AFA7C2FD16FD4C.taxon	etymology	Etymology. The name of this species is dedicated with pleasure to Juan José Morrone Lupi (Zoology Museum, Faculty of Sciences, UNAM), for his magnificent contributions on systematic and biogeography of insects.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977617F4C81AFA7C2FD16FD4C.taxon	materials_examined	Type material (one male, four females): Holotype (male, CC-UAEH): “ México: Hidalgo, La Misión, Lomas del Pericón, bosque mesófilo de montaña perturbado, 1377 m, N 21 ° 07 ’ 110 ”, W 99 ° 06 ’ 2 ”, colecta directa bromelia, colecta # 13, 15 - III- 2008, I. Garrido y J. Márquez cols. ”. Paratypes: Mexico: Hidalgo: “ Tlanchinol, La Cabaña, bosque mesófilo de montaña, 1485 m, N 21 ° 1.357 ’ W 98 ° 38.556 ’, trampa de intercepción de vuelo # 4, 18 a 25 - III- 2006, C. Ortiz y M. C. Pedraza ” (f 1, CC-UAEH). “ Zacualtipán, camino a Tizapán, bosque mesófilo de montaña, 1690 m, N 20 ° 39.076 ’ W 98 ° 36.055 ’, trampa de intercepción de vuelo # 2, 14 al 28 - IV- 2011, J. Márquez col. ” (f 2, CC-UAEH). Puebla: “ Zacapoaxtla, Ex-hacienda Apulco, cascada La Gloria, N 19 ° 54´12 ”, W 97 ° 37´00 ”, 1,508 m, dentro de cañada bosque mesófilo de montaña rodeado por pinos, trampa de intercepción de vuelo, 18 a 28 - V- 2021, familia Márquez-Asiain cols. ” (f 1, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977607F5381AFA4C6FF66F9C9.taxon	description	Figs. 8 b, 10 f, 16 e, 20 f, 24 j, 34	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977607F5381AFA4C6FF66F9C9.taxon	description	Head: transverse, ratio length / width 0.76. Dorsal surface with sulcate longitudinal midline less visible behind front and more visible at front, latter with a foveate area that extends laterad (Fig. 10 f). Eyes nearly 0.5 times the cephalic lateral length, weakly protruding laterally. First antennomere almost as long as antennomeres 2 – 3 combined, 2 slightly shorter than 3, 4 – 5 slightly longer than wide, 6 – 10 almost as long as wide. Mandibles 1.4 times longer than head; each mandible with basal tooth and middle tooth widely separated from each other; mandibular channel well developed, external margin visible and internal margin strongly carinate at base, reaching level of middle tooth, then becoming less visible like impressed line. Apical palpomere of maxillary and labial palpi almost twice as long as preapical palpomere. Head 1.13 times wider than pronotum. Neck with wrinkled microsculpture ventrally. Thorax: dorsal rows of pronotum with six punctures, with posterior punctures more separated from previous punctures; ratio length / width 1.02; almost as wide at anterior corners as at posterior corners (ratio 1.05). Elytra and scutellum with moderately dense fine setae. Prosternum with elevated transverse area near anterior margin, delimited backwards by a clearly visible transverse line. Intercoxal process of mesoventrite shield-shaped, moderately acute and weakly projecting posteriad; transverse discal ridge broadly U-shaped, not meeting margin of intercoxal process laterally. Profemur with external row of spines initiating near base, extending near level of the few apical spines of internal margin, then interrupted as if two or three spines were lacking, ending in two apical spines; spines black, thick and moderately large. Metacoxa with coarse spines moderately dense; metatrochanter with spines as on coxa, but denser; metafemur without row of spines, but with some coarse setae. Tarsomeres flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent depressed area narrow but visible, with sparse wide-superficial punctures combined with fine punctures, tergite 4 also with some wide-superficial punctures at base, remaining surface of each tergite covered with moderately dense, fine punctures. Sternites with punctures similar to those of tergites, but at anterior corners with mesh-like microsculpture looking rough in comparison with that of remaining of their surface, where it is smoother. Male pregenital sternite moderately emarginate at posterior margin (Fig. 16 e). Male genital sternite short (2.14 times longer than wide), very asymmetrical, anterior portion occupying 30 % and posterior portion 70 % of its length, apical emargination very deep (Fig. 20 f). Abdominal styli slender. Aedeagus: length 1.5 mm; elongate in apical half and ovoid in basal half; apex somewhat convex; basal half notably wider than apical half; internal sac visible (Fig. 24 j). Variability. There is the following variation in ratios and measurements: ratio length / width of head in males 0.79 (range 0.71 – 0.85), in females 0.825 (range 0.82 – 0.84); ratio mandibular length / cephalic length in males 1.13 (range 0.88 – 1.35), in females 0.98 (range 0.94 – 1.02); ratio cephalic width / pronotal width in males 1.15 (range 1.07 – 1.27), in females 1.11 (range 1.09 – 1.13); ratio length / width of pronotum in males 1.10 (range 1.03 – 1.15), in females 1.12 (range 1.05 – 1.16); ratio anterior width / posterior width of pronotum in males 1.09 (range 1.06 – 1.14), in females 1.07 (range 1.05 – 1.09). The paralectotype is of paler color than the lectotype, dark-brown, pronotum with dorsal rows with five (left) and six (right) punctures; external row of spines in profemur with spines smaller than in lectotype. Taxonomic comments. Of the group platypterus only B. nigerrimus and B. juanmorronei are completely black, but B. nigerrimus has a transverse head, mandibles as long or longer than head, eyes almost 0.5 times the cephalic lateral length, and a different genital sternite and aedeagus than in B. juanmorronei, which also has an almost square head, slightly widened backwards, mandibles shorter than head and eyes less than 0.5 times the cephalic lateral length. Other black species, such as B. moroni, belong to different groups, making it easier to distinguish them using group characters. Lectotype of this species is designated here taking into account Article 74.7 of the ICZN and its recommendations, to establish more clearly the identity of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977607F5381AFA4C6FF66F9C9.taxon	materials_examined	Type material examined (two males): Lectotype (male, FMNH): “ Jalapa, Mexico / gagates Er. Det. Bernh / nigerrimus Bernh. Typus / Chicago NHMus M. Bernhauer Collection / Lectotype Belonuchus nigerrimus Bernhauer, 1918, Márquez & Asiain des. 2022 ”. Paralectotype: “ Jalapa, Mexiko. Dabberl / nigerrimus, Brnh. Cotypus / Chicago NHMus M. Bernhauer Collection ” (m 1, FMNH). Additional material examined (11 males, five females): Mexico: Hidalgo: “ La Misión, camino al río Moctezuma, N 21 ° 8 ’ 30.6 ”, W 99 ° 5 ’ 49.1 ”, bosque tropical subcaducifolio, en NTP- 80 (calamar), 23 - VI a 5 - VII- 2017, J. Márquez y A. Lora cols. ” (1, CC-UAEH). “ Tenango de Doria, camino a La Viejita, bosque mesófilo de montaña, 1647 m, N 20 ° 19.0 ’ 37.9 ”, W 98 ° 14.0 ’ 39.7 ”, trampa de intercepción de vuelo # 3, 5 a 10 - V- 2013, N. Gutiérrez col. ” (1, CC-UAEH). “ Tianguistengo camino a Santa Mónica, bosque mesófilo de montaña, 1868 m, N 20 ° 43 ’ 5.4 ”, W 98 ° 39 ’ 40.3 ”, trampa de intercepción de vuelo, 7 al 13 - IV- 2009, J. Sánchez, M. Rivero, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Tlanchinol, La Cabaña, bosque mesófilo de montaña, 1485 m, N 21 ° 1.357 ’ W 98 ° 38.556 ’, trampa de intercepción de vuelo # 5, 18 a 25 - III- 2006, C. Ortiz y M. C. Pedraza ” (1, CC-UAEH). “ Tlanchinol camino a Apantlazol, El Pozo, bosque mesófilo de montaña, 1391 m, N 20 ° 59 ’ 6.73 ”, W 98 ° 37 ’ 39.86 ”, NTP- 80 (calamar) # 2, 22 - IV al 10 - V- 2011, J. Márquez col. ” (1, CC-UAEH). Mismos datos excepto: “ NTP- 80 (calamar) # 5 ” (2, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3, 1 - X al 22 - X- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ 22 - IV al 10 - V- 2011 ” (1, CC-UAEH). “ Zacualtipán, camino a Tizapán, boque mesófilo de montaña, 1690 m, N 20 ° 39.076 ’, W 98 ° 36.055 ’, trampa de intercepción de vuelo # 2, 14 al 28 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). Veracruz: “ Córdoba, camino a Plan de Ayala, bosque mesófilo de montaña, 1352 m, N 18 ° 57 ’ 15.2 ”, W 96 ° 58 ’ 41 ”, NTP- 80 (calamar), V a VI- 1999, J. Asiain, Q. Santiago, J. Márquez ” (1, MAAS). “ Huatusco, Coxcontla, bosque mesófilo de montaña perturbado, 1250 m, NTP- 80 (calamar), 14 - I a 11 - II- 1995, M. A. Pensado y Q. Santiago cols. ” (1, QJSJ). Same data, except: “ 29 - VII a 26 - VIII- 1995 ” (1, QJSJ). Same data, except: “ 1 a 29 - VII- 1995, coprotrampa ” (1, QJSJ). Same data, except: “ 6 - V a 3 - VI- 1995, NTP- 80 (calamar) ” (1, QJSJ). “ Huayacocotla, San Antonio, bosque mesófilo de montaña, 1434 m, N 20 ° 40 ’ 32.2 ”, W 98 ° 23 ’ 26.7 ”, NTP- 80 (calamar) # 3, 6 - III a 2 - IV- 2006, F. Ramírez col. ” (1, CC-UAEH). “ Huayacocotla, Helechales, bosque mesófilo de montaña, 1936 m, N 20 ° 37.5 ’ 25 ” W 98 ° 27.6 ’ 49 ”, NTP- 80 (calamar) # 10, 19 - III al 2 - IV- 2011, J. Márquez e I. Martínez cols. ” (1, CC-UAEH). “ Totutla, Mata Oscura, Rancho Zacuapam, selva mediana subcaducifolia, 864 m, N 19 ° 12 ’ 23 ”, W 96 ° 50 ’ 32 ”, hojarasca de riachuelo, 18 - V- 1999, J. Asiain, Q. Santiago y J. Márquez col. ” (1, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777F7F5281AFA042FBBAF838.taxon	description	Figs. 8 c, 10 g, j, 16 o, 20 g, 24 k, 27 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777F7F5281AFA042FBBAF838.taxon	description	Head (Fig. 10 j): subquadrate shape; ratio length / width 0.93. Dorsal surface with microsculpture like wavy lines moderately visible; punctures denser than in majority of species, distributed mainly in posterior 2 / 3 of head; sulcate longitudinal midline faintly visible from anterior margin to posterior 2 / 3 of head; front moderately foveate between antennal insertions and slightly posteriorly. Eyes small, nearly 0.4 times the cephalic lateral length, not protruding laterally. Antennomere 4 elongate, 5 as long as wide, 6 – 10 transverse. Mandibles probably shorter than head (they are broken at apex and closed), each with a middle tooth and possibly with a basal tooth separated from middle tooth; mandibular channel well developed, external and internal margins well separated at base, both carinate, internal margin extending forward like impressed line. Apical palpomere of maxillary palpi 1.4 times longer than preapical palpomere. Apical palpomere of labial palpi almost as long as preapical palpomere. Head 1.08 times wider than pronotum. Ventral surface with microsculpture as on dorsal surface and with very sparse, fine punctures. Thorax: pronotum (Fig. 10 j) 1.19 times longer than wide; almost as wide at anterior corners as at posterior corners (1.06 times); left dorsal row with seven punctures and right dorsal row with eight punctures, dorsal rows occupying slightly more than 3 / 4 of pronotal length. Scutellum with punctures denser than on elytra, latter with moderately dense punctation. Prosternum slightly elevated transversally near anterior margin, but without constriction separating this area from remaining portion. Intercoxal process of mesoventrite oblong shield-shaped with acute apex; transverse discal ridge U-shaped, not meeting margin of intercoxal process laterally, but very close to it. Legs without visible modifications (as in many females of this genus). Tarsomeres weakly flattened dorsally. Abdomen: visible tergites 1 – 3 with indistinct posterior basal transverse carina; adjacent depressed area conspicuous and somewhat deep, with sparse wide-superficial punctures combined with some fine punctures, remaining surface of these tergites, as well as remaining tergites, only with sparse, fine punctures. First visible sternite with posterior basal transverse carina more separated from anterior margin than in sternites 2 – 3, visible sternites 4 – 6 without posterior basal transverse carina; sternites 1 – 4 with apical portion slightly depressed and with some wide-superficial punctures combined with fine punctures, which cover also the rest of the surface and remaining sternites. Variability. Male with total body length 10.4 mm; head (Fig. 10 g) slighly convex dorsally, almost as long as wide (ratio 0.94); posterior corners with wavy roughness, appearing as a faint carina; mandibles shorter than head (ratio 0.84); head 1.16 times wider than pronotum; left dorsal row of pronotum with six punctures and right dorsal row with eight punctures, rows extending on major portion of pronotal length; pronotum 1.25 times longer than wide and almost as wide at anterior corners as at posterior corners; scutellum black, with punctures slightly denser than on elytra, latter with moderately dense punctation; intercoxal process of mesoventrite dark, shield-shaped; transverse discal ridge broadly U-shaped, slightly crenulate; profemur with row of small and sparse spines at external margin; metatrochanter small, with acute apex, with similar shape as in B. aenigmaticus or as in very small males of B. apiciventris; metafemur and metatibia straight; abdominal segments with sparse wide-superficial punctures and fine punctures; pregenital sternite (Fig. 16 – o) with moderate U-shaped emargination at posterior margin, emargination with membranous extension making it difficult to see; genital sternite short (2.3 times longer than wide), weakly asymmetrical, anterior portion occupying 26 % and posterior portion 74 % of its length, apical emargination deep (Fig. 20 g). Abdominal styli slender. Aedeagus 1.25 mm long; cone-shaped, with acute apex, sides becoming gradually wider toward base, which is notably wider than apical half; internal sac little visible (Fig. 24 k). Taxonomic comments. Belonuchus optatus is known only from the partly damaged female holotype, and one non-type male. Two characters allow us to consider it as a valid species for now: the high density of punctures on the dorsal surface of the head (Fig. 10 g) and also the large number of punctures in the dorsal rows of the pronotum (Fig. 10 j): seven on the left and eight on the right that are distributed almost throughout its length. These characters allowed us to propose that one male specimen from the semiarid zone of Querétaro (near the state of Guanajuato) is the second known specimen of this species, which has a trochanter of the posterior legs similar to those of B. aenigmaticus (with only an acute apical spine). Therfore, it was decided to place this species in the platypterus group. It is still necessary, however, to have more specimens to ensure both their identity as valid species and their placement in this group. This species is very similar to B. aenigmaticus, and the characters to distinguish them are located in the taxonomic comments of the latter species, as well as comments on the placement of this pair of species in the platypterus group.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777F7F5281AFA042FBBAF838.taxon	materials_examined	Type material examined: Holotype (female, NHM): “ Philonthus optatus Type D. S. Guanajuato. Mexico. Sallé / Type / Guanajuato / Mexico. Salle Coll. / B. C. A. Col. I. 2. Philonthus optatus, Sharp / Belonuchus formosus apud Sallé ”. Additional material examined (one male): Mexico: Querétaro: “ Peñamiller, Maguey Verde, 2190 m, necrotrampa, 5 a 10 - VIII- 2002, Q. Santiago y L. Delgado cols. ” (m 1, IEXA).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777D7F5081AFA6ABFA03F833.taxon	description	Figs. 8 d, 9 f, 10 d, 11 k, 15 f, 20 h, 24 – l, 30 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777D7F5081AFA6ABFA03F833.taxon	description	Head (Fig. 10 d): subquadrate shape, slightly convex dorsally; ratio length / width in males 0.90 (range 0.86 – 0.93), in females 0.90 (range 0.88 – 0.91). Dorsal surface with sulcate longitudinal midline visible only in anterior half of head; front slightly foveate between antennal insertions. Eyes slightly shorter than 0.5 times the cephalic lateral length, weakly protruding laterally. First antennomere as long as antennomeres 2 – 3 combined, antennomere 3 slightly longer than antennomere 2, 3 – 5 elongate, 6 – 10 transverse. Mandibles (Fig. 10 d) shorter than head (ratio in males 0.855, range 0.81 – 0.92, in females 0.78, range 0.76 – 0.80); left mandible with two small teeth, very close to each other, interspace C-shaped; right mandible with a large middle tooth; basal tooth in both mandibles barely visible; mandibular channel weakly developed, external margin not carinate and internal margin like impressed line extending slightly beyond level of middle tooth, where it is extended slightly toward inside. Apical palpomere of maxillary and labial palpi nearly 1.5 times longer than preapical palpomere. Ventral surface with two setiferous punctures placed in external anterior quarter. Head wider than pronotum (ratio in males 1.22, range 1.15 – 1.28, in females 1.11, range 1.10 – 1.12). Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio in males 1.12, range 1.08 – 1.15, in females 1.11, range 1.08 – 1.14) and slightly wider at anterior corners than at posterior corners (ratio in males and females 1.09, range in males 1.05 – 1.14, in females 1.07 – 1.11). Scutellum with very dense punctures, as on elytra, but wider than on elytra. Prosternum without modifications. Intercoxal process of mesoventrite triangularly scutellum-shaped, distinctly extended posteriad; transverse discal ridge faintly impressed, broadly U-shaped, finely crenulate, reaching very close to margin of intercoxal process laterally (Fig. 11 k). Profemur of both sexes without rows of spines, except for two to three small spines near to apex of internal side. Rest of legs (except tarsomeres) without modifications. Tarsomeres flattened and slightly excavated dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent area moderately depressed and moderately wide; visible tergites 1 – 2 with wide-superficial punctures combined with fine punctures on almost entire surface, becoming less dense toward posterior margin; visible tergites 3 – 4 with widesuperficial punctures denser at anterior half than in posterior half; visible tergites 5 – 6 only with fine punctures. First visible sternite with posterior basal transverse carina completely developed, sternites 2 – 3 with incomplete posterior basal transverse carina, only visible at center; visible sternite 4 without posterior basal transverse carina; sternites with punctures as on tergites, but slightly denser; with coarse, meshed microsculpture near anterior margin of each sternite, at sides is extended backward, remaining of surface of each sternite with finer microsculpture of wavy lines. Male pregenital sternite not emarginate at posterior margin (Fig. 15 f). Male genital sternite moderately elongate (2.6 times longer than wide), slightly asymmetrical, anterior portion occupying 25 % and posterior portion 75 % of its length; apical emargination moderately deep and rather broad (Fig. 20 h). Abdominal styli slender, with external margin slightly curved. Aedeagus: length 1.0 mm; oval-elongate shape; apex subacute; basal half moderately wider than apical half, occupying slightly more than 1 / 2 of aedeagus length, so apical portion appears short; internal sac clearly visible (Fig. 24 – l). Variability. In addition to measurements and ratios included in the description, the apical antennomere, and sometimes also the subapical one, may be paler than previous ones (reddish). Tarsomeres can be reddish brown instead of black; even all legs can be reddish brown. The reddish coloration of fifth visible abdominal segment is darker than that of sixth visible segment, while genital segment is almost yellow. The fine punctures of sixth visible abdominal segment are widely dispersed compared to that of fifth segment. Taxonomic comments. This species is distinguished from the rest of species in this group by being almost completely black, except for the last two visible abdominal segments that are reddish, the left mandible with two middle teeth very close to each other, the tarsomeres markedly flattened dorsally, the male pregenital sternite not emarginate at posterior margin (Fig. 15 f), the male genital sternite moderately elongate (2.6 times longer than wide) (Fig. 20 h) and aedeagus oval-elongate, with slightly acute apex and basal half moderately wider than apical half (Fig. 24 – l). Although the type material of this species was studied, the redescription was based on non-type specimens because the types were returned to the collection of origin earlier.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777D7F5081AFA6ABFA03F833.taxon	materials_examined	Type material examined (one male, one female): Lectotype (male, NHM): “ Philonthus platypterus Type D. S. Cerro Zunil. 4 – 5000 ft. (On the plaque with the specimen) / Type / Cerro Zunil. Guatemala. Champion / B. C. A. Col. I. 2. Philonthus platypterus, Sharp / Sharp Coll. 1905. - 313 / Lectotype Philonthus platypterus Sharp, 1885 des. Chani Posee et al. 2018 ”. Paralectotype: same data as lectotype, except: “ Paralectotype Philonthus platypterus Sharp, 1885, des. Chani Posse et al. 2018 ” (f 1, NHM). Additional material examined (seven males, three females): Mexico: Hidalgo: “ Juárez, bosque mesófilo perturbado, 1970 m, N 20 ° 47 ’ 9.6 ”, W 98 ° 49 ’ 5.2 ”, trampa de intercepción de vuelo # 2, 7 al 14 - III- 2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols. ” (1, CC-UAEH). “ Tenango de Doria, camino a La Viejita, bosque mesófilo de montaña, 1647 m, N 20 ° 19.0 ’ 37.9 ”, W 98 ° 14.0 ’ 39.7 ”, trampa de intercepción de vuelo # 3, 5 a 10 - V- 2013, N. Gutiérrez col. ” (2, CC-UAEH). “ Tepehuacán de Guerrero, Chilijapa, bosque mesófilo de montaña, 1401 m, N 21 ° 01.2 ’ 5.1 ”, W 98 ° 51.8 ’ 2.1 ”, trampa de intercepción de vuelo # 2, 27 - VIII al 10 - IX- 2011, J. Márquez col. ” (1, CC-UAEH). “ Tlanchinol, camino a Apantlazol, El Pozo, bosque mesófilo de montaña, 1391 m, N 20 ° 59 ’ 6.73 ”, W 98 ° 37 ’ 39.86 ”, trampa de intercepción de vuelo # 1, 22 - IV al 10 - V- 2011, J. Márquez e I. Martínez cols. ” (1, CC-UAEH). Same data, except: “ 1 al 22 - X- 2011 ” (1, CC-UAEH). “ Zacualtipán, camino a Tizapán, bosque mesófilo de montaña, 1690 m, N 20 ° 39.076 ’ W 98 ° 36.055 ’, trampa de intercepción de vuelo # 2, 14 al 28 - IV- 2011, J. Márquez col. ” (2, CC-UAEH). Puebla: “ Zacapoaxtla, Ex-hacienda Apulco, cascada La Gloria, N 19 ° 54´12 ”, W 97 ° 37´00 ”, 1,508 m, dentro de cañada bosque mesófilo de montaña rodeado por pinos, trampa de intercepción de vuelo, 18 a 28 - V- 2021, familia Márquez-Asiain cols. ” (1, MAAS) Veracruz: “ Córdoba, camino a Plan de Ayala, bosque mesófilo de montaña, 1352 m, N 18 ° 57 ’ 15.2 ”, W 96 ° 58 ’ 41 ”, NTP- 80 (calamar), 20 - III al 17 - IV- 1999, J. Asiain, Q. Santiago y J. Márquez cols. ” (1, MAAS). Group 7: viridipennis Included species: B. abnormalis (Shap, 1885), B. pectinipes Bernhauer, 1910, B. viridipennis Baudi di Selve, 1848, and Belonuchus sp. Q.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777D7F5081AFA6ABFA03F833.taxon	diagnosis	Diagnosis of the viridipennis group: without any of the male sexual structures indicated in the previous groups; head without temporal carina; mandibles almost as long as head (ratio mandibular length / cephalic length 0.82 - 1.09; Fig. 9 a), right mandible with two medial teeth, one of them (usually the longest one) in ventral position and the other in dorsal position (Figs. 9 g – i); body color mainly black (sometimes with the sixth or fifth and sixth abdominal segments reddish); specimens of small size (body length 6.6 - 11.9 mm); tarsomeres somewhat flattened dorsally; aedeagus with reduced paramere (Figs. 25 b – e).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777B7F5681AFA6ABFE0DFC65.taxon	description	Figs. 8 f, 17 a, 20 j, 25 b, 30 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777B7F5681AFA6ABFE0DFC65.taxon	description	Head: oval, slightly narrowed posteriad, dorsally flattened; ratio length / width in males 0.91 (range 0.89 – 0.92), in females 0.95 (range 0.92 – 0.96). Dorsal surface with faintly visible microsculpture like wavy lines; punctures sparser than in majority of species; sulcate longitudinal midline visible only at front; front moderately foveate between antennal insertions and slightly posteriorly. Eyes nearly 0.5 times the cephalic lateral length, slightly protruding at sides. First antennomere as long as antennomeres 2 – 3 combined, antennomere 3 slightly longer than 2, 4 – 5 elongate, 6 – 10 transverse. Mandibles shorter than head (ratio in males 0.82, range 0.80 – 0.84, in females 0.76, range 0.72 – 0.78); right mandible with a middle, acute tooth of moderate size, and a very small tooth (difficult to see) in ventral position below previous tooth; left mandible with two middle teeth very close to each other, the longer in ventral position and the smaller in dorsal position; in both mandibles basal tooth is slightly discernible; mandibular channel well developed, narrow, external margin not carinate and internal margin slightly carinate from base to near level of the most apical middle tooth, where it becomes an impressed line that extends slightly higher. Apical palpomere of maxillary and labial palpi almost twice as long as preapical palpomere, aplical palpomere with faint microsculpture of longitudinal lines and microgranules. Head 1.13 times wider than pronotum in males (range 1.11 – 1.14) and 1.07 times in females (range 1.04 – 1.09). Neck in ventral view with mesh-like microsculpture. Thorax: pronotum with microsculpture as on head, but more conspicuous; each dorsal row with three punctures, with anterior puncture separated from anterior margin more than usual and third puncture more distinctly separated from two previous; pronotum 1.24 times longer than wide (males without variation, in females range 1.17 – 1.29); at anterior corners almost as wide as at posterior corners (ratio in males 1.09, range 1.08 – 1.09, in females 1.06, range 1.04 – 1.09). Scutellum and elytra with punctures moderately dense, punctures on elytra finer than on scutellum. Prosternum slighly impressed in a narrow strip close to anterior margin. Intercoxal process of mesoventrite triangularly scutellum-shaped, apex only weakly acute; transverse discal ridge well developed, broadly V-shaped, reaching very close to margin of intercoxal process laterally. Profemur of males with external margin completely visible, but internal margin visible only at apex; row of spines at external margin initiating in basal third, where spines are very small, and ending near apical third with last three to four spines notably larger than previous spines; internal apex with three to four small spines. Remainder of legs without modifications. Tarsomeres very slender, moderately flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent area weakly depressed on tergites 1 – 2, and even less so on tergite 3; with wide-superficial punctures combined with fine punctures that cover anterior 2 / 3 of tergites 1 – 2, anterior half of tergites 3 – 4, and anterior 1 / 4 of tergite 5; tergite 6 only with fine punctures. Visible sternites 1 – 4 with posterior basal transverse carina well developed and with punctures as on tergites, but slightly denser. Male pregenital sternite with a narrow, moderately deep emargination at posterior margin, V-shaped (Fig. 17 a). Male genital sternite very elongate (3.16 times longer than wide), almost symmetrical, anterior portion occupying 17 % and posterior portion 83 % of its length, apical emargination moderately deep (Fig. 20 j). Abdominal styli slender. Aedeagus: length 1.1 mm; elongate shape; apex pointed; narrowest part of apical portion occupying more than 1 / 2 of apical portion and wider basal portion occupying near 1 / 3 of aedeagus length; basal part moderately wider than apical part; internal sac not visible (Fig. 25 b). Variability. In addition to the variation in measurements and ratios included in the description, it was only found that in females the head has more oval sides and is slightly narrowing posteriad. Taxonomic comments. Belonuchus abnormalis is easily distinguished from B. pectinipes and B. viridipennis by having the last two visible abdominal segments reddish (except anterior third of fifth segment) and only three punctures in each dorsal row of pronotum. It could also be confused with Belonuchus sp. Q for its similar abdominal coloration, but B. abnormalis has an oval head, three punctures in each dorsal row of pronotum, male pregenital sternite with a narrow, moderately deep V-shaped emargination at posterior margin (Fig. 17 a), male genital sternite almost symmetrical, with apical emargination moderately deep (Fig. 20 j), and aedeagus with elongate shape (Fig. 25 b). While Belonuchus sp. Q has a subquadrangular head, five punctures in each dorsal row of pronotum, male pregenital sternite with distinctly deep, V-shaped emargination at posterior margin (Fig. 17 e), male genital sternite very asymmetrical, with apical emargination deep (Fig. 20 m), and aedeagus acute in apical portion and oval in basal portion (Fig. 25 e). Although the type material of this species was studied, the redescription was based on non-type specimens because the types were returned to the collection of origin prior to this activity.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777B7F5681AFA6ABFE0DFC65.taxon	materials_examined	Type material examined (one male, one female): Lectotype (male, NHM): “ Philonthus abnormalis Type D. S. Oaxaca. Mexico. Höge (on the card with the specimen) / Type / Oaxaca, Mexico. Hoege / B. C. A. Col. I. 2. Philonthus abnormalis, Sharp / Sharp Coll. 1905. - 313 / Lectotype Philonthus abnormalis des. Chani Posse et al. 2018 ”. Paralectotype: same data as lectotype, except: “ Sp. figured / Paralectotype Philonthus abnormalis des. Chani Posse et al. 2018 ” (f 1, NHM). Additional material examined (three males, four females): Mexico: Estado de México: “ Ixtapan de la Sal, 2 km S de Zacango, N 18 ° 58 ’ 05 ”, W 99 ° 51 ’ 31 ”, 2000 m, en bromelia, 18 - III- 2004, L. Cervantes col. ” (2, IEXA). Oaxaca: “ Santiago Yosondua, camino a El Vergel, bosque de encino, 1893 m, N 16 ° 50 ’ 10 ”, W 97 ° 34 ’ 33 ”, en bromelias, 7 - VIII- 2001, J. Asiain, S. Bautista y J. Márquez cols. ” (2, MAAS). “ Santiago Yosondua, camino a El Vergel, La Cascada, bosque de encino, 1905 m, N 16 ° 50 ’ 49.6 ”, W 97 ° 34 ’ 470.5 ”, sobre bromelias, 12 - VII- 2002, J. Asiain y J. Márquez cols. ” (2, MAAS). “ Santiago Yosondua, La Cascada, 1905 m, N 16 ° 50 ’ 50 ”, W 97 ° 34 ’ 47 ”, bosque de pino-encino, en bromelias, 9 - VIII- 2001, S. Bautista, J. Asiain y J. Márquez cols. ” (1, CC-UAEH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777A7F5581AFA5EEFD05FA9D.taxon	description	Figs. 8 g, 17 b, 20 k, 25 c, 32 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777A7F5581AFA5EEFD05FA9D.taxon	description	Head: oval shape, posterior corners convex; ratio length / width 0.84. Dorsal surface with sulcate longitudinal midline weakly visible only at front; front moderately foveate between antennal insertions. Eyes slightly less than 0.5 times the cephalic lateral length, slightly protruding laterally. First antennomere as long as antennomeres 2 – 3 combined, 2 slightly shorter than 3, 4 elongate, 5 as long as wide, 6 – 10 transverse. Mandibles 1.09 times as long as head; right mandible with three middle teeth very close to each other, with ventral tooth the biggest; left mandible with two middle teeth in dorsal position very close to each other; both mandibles with a small basal tooth; mandibular channel with external and internal margins well developed. Apical palpomere of maxillary and labial palpi almost twice as long as preapical palpomere. Head 1.16 times wider than pronotum. Neck with wrinkled microsculpture in ventral view. Thorax: pronotum with left dorsal row with five punctures and right dorsal row with six punctures; pronotum slightly longer than wide (ratio 1.15) and somewhat wider at anterior corners than at posterior corners (ratio 1.13). Elytra and scutellum glossy, with sparse, fine setae and smooth spaces. Prosternum slightly elevated close to anteri- or margin. Intercoxal process of mesoventrite elongate scutellum-shaped; transverse discal ridge broadly U-shaped, not meeting margin of intercoxal process laterally. Profemur with row of spines at external margin, from its base to 3 / 4 of its length, spines increasing in size from base to apex, where they are very conspicuous (as long as, or longer than last tarsomere of anterior legs); apical spines of internal margin smaller than apical spines of external margin. Posterior legs with long, black spines on coxae and trochanters without regular order; femora and tibiae without modifications. Tarsomeres moderately flattened dorsally. Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent area moderately depressed and narrow, with some wide-superficial punctures combined with fine punctures, outside of these depressions and on remaining tergites only with fine punctures. Sternites with punctures and setae as on tergites. Male pregenital sternite moderately emarginate at posterior margin (Fig. 17 b). Male genital sternite very elongate (3.1 times longer than wide), moderately symmetrical, anterior portion occupying 23 % and posterior portion 77 % of its length, apical emargination moderately deep (Fig. 20 k). Abdominal styli slender. Aedeagus: length 1.15 mm; very elongate and slender; apex rounded; basal portion slightly wider than apical portion (best seen in lateral view), apical portion nearly 2 / 3 of aedeagus length; internal sac visible (Fig. 25 c). Variability. The second male specimen of the type series has an iridescent sheen and is dorsally flatter than the lectotype; longitudinal midline of head inconspicuous in anterior half, in addition to foveate area on front; tarsomeres slightly flattened in dorsal view; elytra and particularly on abdomen with long to very long setae; areas adjacent to posterior basal transverse carina of first three visible abdominal tergites slightly depressed and almost smooth. Total body length 8.6 mm (althougth measured with last two abdominal segments not fully extended); ratio length / width of head 0.84; ratio mandibular length / cephalic length 1.07; ratio cephalic width / pronotal width 1.23; ratio length / width of pronotum 1.19; ratio anterior width / posterior width of pronotum 1.13. Females (two specimes of type series) with head flattened rather than convex; right mandible with middle two teeth of small size; dorsal rows of pronotum with five punctures (both rows); profemora with fewer spines at external margin, but two to three apical spines as long as last tarsomere of anterior legs. Total body length 10.3 and 8.9 mm respectively; ratio length / width of head 0.95 and 1.00; ratio mandibular length / cephalic length 0.75 and 0.87; ratio cephalic width / pronotal width 1.04 (both); ratio length / width of pronotum 1.22 and 1.29; ratio anterior width / posterior width of pronotum 1.04 and 1.09. Taxonomic comments. This species is similar to B. viridipennis in size and color pattern. It can be distinguished because B. pectinipes is more reddish brown, its head is oval, the left mandible has a basal tooth and two middle teeth, the right mandible has a basal tooth and three middle teeth, pronotum slightly wider at anterior corners than at posterior corners (ratio 1.13 times), the femora of posterior legs are without spines, the coxae and trochanters of posterior legs of males are with long black spines, and its aedeagus is very elongate and slender, with apex rounded (Fig. 25 c). In contrast, B. viridipennis has a subquadrate head, left mandible with only one middle tooth of peculiar shape (Fig. 9 g), right mandible with two teeth, ventral tooth longer than dorsal tooth, pronotum wider at anterior corners than at posterior corners (ratio 1.23 – 1.53), femora of posterior legs of both sexes with two rows of spines, coxae and trochanters of posterior legs of males without spines, and aedeagus with elongate shape at anterior 2 / 3, and oval shape at basal third, with pointed apex (Fig. 25 d). As was commented under B. cariniventris, it is remarkable that only the type specimens of B. pectinipes are known, since Córdoba is a site in Veracruz where collections have been made for a long time and until relatively recently. Lectotype of this species is designated here in order to clearly establish the identity of this species.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E8789777A7F5581AFA5EEFD05FA9D.taxon	materials_examined	Type material examined (two males, two females): Lectotype (male, FMNH): “ Cordoba, Mex. Ver. Dr. A. Fenyes / pectinipes Brnh. Cotypus / Chicago NHColl. M. Bernhauer Collection / Lectotype Belonuchus pectinipes Bernhauer, 1910, Márquez & Asiain des. 2022 ”. Paralectotypes: same data as lectotype, except: “ Typus ” (m 1, FMNH); same data as lectotype (f 2, FMNH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977797F5B81AFA3F6FB2CFDFD.taxon	description	Figs. 8 h, 9 g, 12 a, i, 13 j, 17 c, 20 - l, 25 d, 33 a	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977797F5B81AFA3F6FB2CFDFD.taxon	description	Head: quadrangular, wider than long (ratio in male 0.81, in females 0.87, range 0.87 – 0.91). Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front plane, not foveate between antennal insertions. Eyes 0.45 times the cephalic lateral length, slightly protruding at sides. Antennomere 4 as long as wide, 5 – 10 transverse. Mandibles (Fig. 9 g) in male almost as long as head (ratio 0.95), in females shorter than head (ratio 0.85, range 0.81 – 0.90); base of mandibles with coarse, mesh-like microsculpture; left mandible with a large middle tooth of characteristic shape (Fig. 9 g), right mandible with two middle teeth, the large one in ventral position close to the small dorsal tooth; mandibles without basal tooth; mandibular channel well developed, external margin moderately carinate, internal margin like impressed line extending forward beyond level of middle teeth. Apical palpomere of maxillary palpi 1.5 times longer than preapical palpomere; apical palpomere of labial palpi nearly twice the length of preapical palpomere. Ventral surface with some sparse, fine punctures. Head notably wider than pronotum (ratio in male 1.41, in females 1.23, range 1.21 – 1.25). Thorax: each dorsal row of pronotum with five punctures; pronotum longer than wide (ratio in male 1.25, in females 1.20, range 1.19 – 1.21) and wider at anterior corners than at posterior corners (ratio in male 1.23, in females 1.53, range 1.35 – 1.90); lateral margins slightly sinuous. Scutellum with punctures larger and denser than on elytra; elytra with faint metallic reflections contrasting with scutellum that is without these reflections; with fine, dense punctures. Prosternum near to anterior margin slightly elevated transversally, delimited backwards by an impressed line. Intercoxal process of mesoventrite (Fig. 12 a) scutellum-shaped; transverse discal ridge well developed, broadly U-shaped, reaching close to margin of intercoxal process laterally, but not meeting it. Profemur of male (Fig. 12 i) and large females with external row of spines difficult to discern because they are very small and are mixed with dense setae, row initiating at base and ending in apical third; internal margin only with three to four spines larger than apical external spines. Metafemur of male (Fig. 13 j) with two widely separated rows of spines, external row with spines slightly longer than spines of internal row, internal row of spines in females better developed than external row of spines. Tarsomeres slender, slightly flattened dorsally. Abdomen: first three visible tergites without posterior basal transverse carina, but anterior third (or slightly more) is clearly depressed and with very dense wide-superficial punctures, which in combination with mesh-like microsculpture, gives a rough appearance; this pattern gradually disappears from the depression toward posterior margin and is transformed into fine punctures with also finer microsculpture like wavy lines; visible tergite 4 without depression, but with a pattern similar to that of tergite 3, although less extensive in anterior half; visible tergites 5 – 6 almost only with fine punctures and microsculpture. Visible sternites 1 – 3 with posterior basal transverse carina, sternites 4 – 6 without posterior basal transverse carina; punctures and microsculpure similar to that on tergites. Male pregenital sternite with moderate, very broadly V-shaped emargination at posterior margin (Fig. 17 c). Male genital sternite very elongate (3.62 times longer than wide), almost symmetrical, anterior portion occupying 16 % and posterior portion 84 % of its length, apical emargination deep (Fig. 20 – l). Abdominal styli slender. Aedeagus: length 0.85 mm; elongate shape in anterior 2 / 3 and oval shape in basal third; apex pointed, below apex sides slightly wider than in middle part, but in basal third wide, widest part is best observed in lateral view; internal sac slightly visible (Fig. 25 d). Variability. In addition to the little variation related to measurements and ratios included in the description, it was noted that the iridescent sheen or brightness of elytra is, at best, slightly visible in most specimens and in some it is not apparent. The sulcate longitudinal midline in front was indistinct in a specimen, and extended further back from cephalic half. The size of teeth of mandibles varies in proportion to the size of specimens, as well as the more distinct development of punctures and coarse microsculpture of abdomen, which is more pronounced in larger specimens. Taxonomic comments. Belonuchus viridipennis could be mainly confused with B. pectinipes, but the main differences have been highlighted in the taxonomic comments of the latter species. It was not possible to review any type of B. viridipennis (type locality: Novae Valenciae, Venezuela) or B. mexicanus (type locality: “ Mexique ”). In the case of the latter species, the material may have been lost (personal communication, A. A. Gusakov, curator of Coleoptera, Zoological Museum of the Moscow Lomonosov State University). However, the comparison of information included in the original descriptions and the redescription of B. mexicanus by Silvestri (1945), as well as the wide distribution from Mexico to Brazil and Argentina, allowed us to propose both species to be synonyms. This facilitates the recognition of B. mexicanus (now a synonym of B. viridipennis), of which there is still very little is known in Mexico. The following are several of the same or very similar characters mentioned in the original description of B. viridipennis and B. mexicanus, and the redescription of B. mexicanus by Silvestri (1945), which support the proposal that they are synonyms: small body size; color body black with faint metallic green elytra; both dorsal and ventral teeth of mandibles (mainly on the left); anterior part of pronotum slightly wider than posterior part and convex at sides, dorsal series each composed by five big punctures, and six additional smaller punctures outside each dorsal series; rows of spines on the pro- and metafemora; pregenital sternite emarginate at posterior margin of males, and the small, slender aedeagus.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977797F5B81AFA3F6FB2CFDFD.taxon	materials_examined	Material examined (nine males, nine females): Mexico: Chiapas: “ 8 mi N Pueblo Nuevo Solistahuacán, 6000 ’, 26 a 27 - VIII- 1973 / under bark, A. Newton ” (m 1, FMNH). Hidalgo: “ 3 km N de Tlanchinol, 1450 m, bosque mesófilo de montaña, N 21 ° 1.328 ’, W 98 ° 38.77 ’, sobre vegetación, 1 - V- 2003, J. Asiain y J. Márquez cols. ” (1, MAAS). Morelos: “ Mexicapa, bosque de pino, zona 1, NTP- 80 calamar, 1 a 25 - IV- 1993, A. Soria, C. Cabello y E. Córdoba cols. ” (1, MAAS). “ Tlayacapan, San José de los Laureles, NTP- 80, localidad 4, selva baja caducifolia, XII- 1995, K. Villavicencio y J. Márquez cols. ” (2, MAAS). Veracruz: “ Tequila, Kohyomyxtla, 1800 m, coprotrampa, 1 a 30 - V- 2011, L. Lara et al. cols. ” (f 1, IEXA). “ Jalapa / viridipennis det. Bernh. / Chicago NHMus, M. Bernhauer Collection ” (2, FMNH). “ Orizaba / viridipennis det. Bernh. / Chicago NHMus, M. Bernhauer Collection ” (1, FMNH). “ Jalapa, Höge, Belonuchus dejectus D. S. (in the plaque with the specimen) / Jalapa, Hoege / B. C. A. Col. I. 2. Belonuchus viridipennis Baud., dejectus Sharp / Chicago Nat. Hist. Mus. (ex D. Sharp Colln. by Exchange with Brit. Mus. Nat. Hist.) (m 1, FMNH). Guatemala: “ San Joaquin, Vera Paz. Champion / B. C. A. Col. I. 2. Belonuchus viridipennis Baud., dejectus Sharp / Chicago Nat. Hist. Mus. (ex D. Sharp Colln. by Exchange with Brit. Mus. Nat. Hist.) (2, FMNH). “ Truqui, Mexico / Chicago NHMus, M. Bernhauer Collection ” (6, FMNH).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977767F5981AFA337FCE1F959.taxon	description	Figs. 9 b, k, 12 c, 15 g, 20 n, 25 f, 29 b Total body length 7.6 mm. Body black, shiny, except elytra that are metallic blue, legs dark-brown and genital segment reddish. Head: oval (Fig. 10 h); ratio length / width 1.03. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; punctures slightly sparser than in majority of species; front moderately foveate between antennal insertions. Eyes slightly more than 0.5 times the cephalic lateral length, notably protruding at sides. First antennomere shorter than 2 – 3 combined (0.75 times), antennomere 2 slightly shorter than 3 (0.8 times), antennomere 3 the smallest and oblong, 4 as long as wide, 5 – 10 transverse; antennomeres 4 – 10 of characteristic shape, like pieces of a rosary (Fig. 9 k). Mandibles shorter than head (ratio 0.78); narrow at base, each with a small middle tooth, no basal tooth discernible; mandibular channel slightly developed, with external margin not carinate and internal margin like impressed line extending forward slightly beyond level of middle tooth. Apical palpomere of maxillary palpi 1.8 times longer than preapical palpomere; apical palpomere of labial palpi almost as long as preapical palpomere. Head almost as wide as pronotum (ratio 1.03). Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio 1.1) and almost as wide at anterior corners as at posterior corners (ratio 1.03). Scutellum very large, nearly 1 / 4 of elytral length measured at center, with punctures wider and denser than on elytra, latter with fine and sparse punctation. Prosternum with a narrow transverse area near anterior margin delimited backwards by slightly visible impressed line. Intercoxal process of mesoventrite (Fig. 12 c) triangularly scutellum-shaped, but with its apex not as acute; transverse discal ridge well developed like curved wave, laterally reaching very close to margin of intercoxal process. Legs long and slender, with few setae and spines, particularly hind legs. Profemur without row of spines at external margin, internal margin visible only near apex of femur where having three to four small spines. Metafemur without modifications or spines. Tarsomeres very slender and not flattened dorsally. Abdomen: punctures and setae at medial part of each tergite very sparse, majority of setae large and placed at all margins of each tergite, so dorsal part of abdomen looks very glossy. Visible tergites 1 – 3 with fine posterior basal transverse carina, adjacent area weakly depressed, on tergite 3 practically not visible. Visible sternites 1 – 3 with entire surface covered with dense, wide-superficial punctures, combined with fine punctures, its density decreasing from anterior to posterior margin and from first visible to fifth visible sternite, on sixth visible sternite only with fine punctures. Male pregenital sternite not emarginate at posterior margin (Fig. 15 g). Genital segment yellowish. Male genital sternite very elongate (3.14 times longer than wide), moderately asymmetrical, anterior portion occupying 36 % and posterior portion 64 % of its length, apical emargination very deep (Fig. 20 n). Abdominal styli slender. Aedeagus: length 1.0 mm; oval in basal half and subparallel in apical half; apex subacute; basal half wider than apical half; internal sac weakly developed (Fig. 25 f). Variability. Total body length in males 7.35 mm (range 6.3 – 8.1 mm), in females 7.41 mm (range 6.6 – 8.2 mm); ratio length / width of head in males 0.93 (range 0.90 – 0.95), in females 0.94 (range 0.91 – 0.95); ratio mandibular length / cephalic length in males 0.73 (range 0.60 – 0.85), in females 0.72 (range 0.70 – 0.75); ratio cephalic width / pronotal width in males 1.12 (range 1.07 – 1.16), in females 1.10 (range 1.05 – 1.16); ratio length / width of pronotum in males 1.13 (range 1.09 – 1.17), in females 1.15 (range 1.10 – 1.21); ratio anterior width / posterior width of pronotum in males 1.05 (range 1.03 – 1.08), in females 1.04 (range 1.00 – 1.08). Furthermore, the dorsal surface of head is more convex in some specimens; the metallic hue of elytra is mainly bluish, but may be slightly greenish or more rarely purplish violet; anterior portion of prosternum may not show the impressed line that separates it from the rest of prosternum; wide-superficial punctures can be dense on first visible sternite, less dense on second sternite, sparse on third sternite and very sparse on fourth sternite. Taxonomic comments. The main differences to distinguish B. cyanipennis from B. godmani are the same as those included in the key and since there are only two species in this group, it is not considered necessary to repeat them.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977767F5981AFA337FCE1F959.taxon	etymology	Etymology. The name of this species is a combination of the words “ cyaneus ” and “ pennis ”, which denotes the dark blue metallic coloration of its elytra, while the rest of the body is glossy black.	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977767F5981AFA337FCE1F959.taxon	materials_examined	Type material (15 males, nine females): Holotype (male, CC-UAEH): “ México: Hidalgo, Tlanchinol, cerca de La Cabaña, N 21 ° 01.328´, W 98 ° 38.770´, bosque mesófilo de montaña, 1450 m, en hongo de repisa de tronco, 16 - IV- 2003, J. Márquez y J. Asiain cols. ”. Paratypes: Mexico: Hidalgo: “ Tenango de Doria, camino a La Viejita, N 20 ° 19´37.9 ”, W 98 ° 14´39.7 ”, bosque mesófilo de montaña, 1647 m, NTP- 80 (calamar) # 5, 29 - III a 12 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). “ Tlanchinol, cerca de La Cabaña, N 21 ° 01.328´, W 98 ° 38.770´, bosque mesófilo de montaña, 1450 m, en hongo de repisa de tronco, 16 - IV- 2003, J. Márquez y J. Asiain cols. ” (9, CC-UAEH). Same data, except: “ en tronco caído, 8 - XII- 1997, J. Márquez col. ” (1, MAAS). “ Zacualtipán, camino a Santo Domingo, N 20 ° 37´44.9 ”, W 98 ° 34´51.06 ”, en troncos, 6 a 7 - X- 2006, J. Márquez y J. Asiain cols. ” (3, CC-UAEH). “ Zacualtipán, camino a Tizapán, N 20 ° 39.076´, W 98 ° 36.055´, bosque mesófilo de montaña, 1690 m, trampa de intercepción de vuelo # 1, 14 - IV a 28 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 3, 20 - IX a 4 - X- 2011 ” (1, CC-UAEH). Puebla: “ Zacapoaxtla, Ex-hacienda Apulco, cascada La Gloria, N 19 ° 54´12 ”, W 97 ° 37´00 ”, 1,508 m, dentro de cañada bosque mesófilo de montaña rodeado por pinos, trampa de intercepción de vuelo, 18 a 28 - V- 2021, familia Márquez-Asiain cols. ” (3, MAAS). Veracruz: “ Córdoba, camino a Plan de Ayala, N 18 ° 57´15.2 ”, W 96 ° 58´41 ”, bosque mesófilo de montaña, 1352 m, en troncos caídos con hongos, 19 - V- 1999, J. Asiain, Q. Santiago y J. Márquez cols. ” (4, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977757F5F81AFA13FFD33FCF1.taxon	description	Figs. 9 c, j, 10 i, 16 g, 20 – o, 25 g, 33 b	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977757F5F81AFA13FFD33FCF1.taxon	description	Head: oval shape, slightly narrowed posteriad, dorsal surface convex (Fig. 10 i); ratio length / width of head in male 0.94 (range 0.89 – 0.96), in females 0.99 (range 0.96 – 1.04). Dorsal surfaces with microsculpture slightly visible, like wavy lines; with punctures sparser than in majority of species; sulcate longitudinal midline weakly visible in anterior half of head; front notably foveate between antennal insertions. Eyes nearly 0.5 times the cephalic lateral length, slightly protruding at sides. First antennomere slightly shorter (0.9 times) than 2 – 3 combined, antennomere 3 longer than 2, 4 – 5 as long as wide, 6 – 10 transverse (Fig. 9 j). Mandibles shorter than head (ratio in males 0.82, range 0.76 – 0.92, in females 0.76, range 0.70 – 0.83); each with a middle tooth, right tooth slightly longer than left tooth; mandibular channel well developed, narrow, external margin carinate, internal margin like impressed line, extending beyond of level of middle tooth. Apical palpomere of maxillary palpi 1.7 times longer than preapical palpomere; apical palpomere of labial palpi 1.4 times longer than preapical palpomere. Head slightly wider than pronotum (ratio in males 1.14, range 1.09 – 1.19, in females 1.08, range 1.03 – 1.17). Thorax: each dorsal row of pronotum with five punctures; pronotum longer than wide (ratio in males 1.21, range 1.17 – 1.29, in females 1.23, range 1.19 – 1.27) and almost as wide at anterior corners as at posterior corners (ratio in males 1.06, range 1.04 – 1.10, in females 1.04, range 1.00 – 1.09). Scutellum with wide punctures somewhat sparse, but more noticeable than punctures on elytra, in addition to conspicuous microsculpture like wavy lines that is not visible on elytra; elytra with glossy surface and very sparse punctures that are slightly broad. Prosternum impressed near anterior margin, followed by a transverse elevated area that is delimited backwards by an impressed line. Intercoxal process of mesoventrite triangularly scutellum-shaped; transverse discal ridge very broadly U-shaped, not meeting margin of intercoxal process laterally. Profemur of males and females with external margin completely developed, but without row of spines; internal margin only visible near apex of femur, where having three to four small spines. Legs long and slender, without modifications. Tarsomeres slender and slightly flattened dorsally. Abdomen: glossy, all tergites covered with sparse, fine punctures; first three visible tergites with posterior basal transverse carina well developed; adjacent area slightly depressed, almost flat; sternites with wide-superficial punctures combined with fine punctures, wide-superficial punctures becoming less dense from anterior to posterior margin and first to fifth visible sternites, sixth visible sternite only with fine punctures. Male pregenital sternite very slightly emarginate at posterior margin (Fig. 16 g). Male genital sternite very elongate (3.2 times longer than wide), very asymmetrical, anterior portion occupying 28 % and posterior portion 72 % of its length, apical emargination not deep (Fig. 20 – o). Abdominal styli slender. Aedeagus: length 1.1 mm; oval-elongate shape; sides concavely narrowed to form a slender apical portion, but with rounded apex; internal sac visible, mainly in lateral view (Fig. 25 g). Variability. In addition to the variation in measurements included in the redescription, there is great variability in the metallic hue of elytra, from purplish (or violaceous) and green to gold; sulcate longitudinal midline of head can be distinguished further back from middle of head, in most specimens it is only seen in anterior half; in some specimens the most foveate part of front gives the appearance of being a very broad pit (which would resemble specimens of Chroaptomus); punctures on elytra vary somewhat in density; visible tergite 4 of some specimens with emarginate posterior basal transverse carina at sides, not developed at center. Taxonomic comments. Chani-Posse et al. (2018 b) point out that this species is not part of the haemorrhoidalis clade and that in a future study they will exclude it from Belonuchus; as this has not yet happened, it remains part of this genus. A quick distinction between B. godmani and B. cyanipennis is the metallic blue color on the head of the first species and black on the head of the second species. Other differences are found in the above key. The type material of this species was not studied, but was previously revised by Márquez (2011).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
038E878977757F5F81AFA13FFD33FCF1.taxon	materials_examined	Material examined (50 males, 37 females): Mexico: Hidalgo: “ Molango, Acuatitlán, N 20 º 45 ’ 38.4 ”, W 98 º 42 ’ 50.7 ”, 1715 m, bosque mesófilo de montaña, en troncos con hongos, 10 - VI- 2008, J. Márquez, J. Bueno y M. García cols. ” (3, CC-UAEH). “ Tenango de Doria, El Potrero, bosque mesófilo de montaña, N 20 ° 18 ’ 49.5 ”, W 98 ° 13 ’ 48.3 ”, 2185 m, en tronco en descomposición, 25 - IV- 2009, M. Torres, M. Rivero, J. Sánchez y J. Márquez cols. ” (1, CC-UAEH). “ Tlanchinol, cerca de La Cabaña, N 21 º 01.328 ’, W 98 º 38.770 ’, 1450 m, bosque mesófilo de montaña, en hongos de repisa de troncos, 16 - IV- 2003, J. Márquez y J. Asiain cols. ” (4, CC-UAEH). “ Zacualtipán, La Mojonera, N 20 º 37 ’ 59 ”, W 98 º 35 ’ 48 ”, 1886 m, bosque mesófilo de montaña perturbado, en troncos podridos, 25 - IV- 2002, J. Asiain y J. Márquez cols. ” (9, MAAS). Same data, except: “ NTP- 80 (calamar), 28 - II a 29 - IV- 2004 ” (1, CC-UAEH). “ Zacualtipán, camino a Santo Domingo, N 20 º 37 ’ 44.9 ”, W 98 º 34 ’ 51.06 ”, 1830 m, bosque mesófilo de montaña, en troncos, 6 y 7 - X- 2006, J. Márquez y J. Asiain cols. ” (6, CC-UAEH). “ Zacualtipán, camino a Santo Domingo, N 20 º 38 ’ 0.7 ”, W 98 º 34 ’ 00.5 ”, 1800 m, bosque mesófilo de montaña, en hongos de troncos, 31 - X- 2003, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Zacualtipán, 2 km antes de Tizapán, N 20 º 38 ’ 44.5 ”, W 98 º 36 ’ 7.2 ”, 1790 m, bosque mesófilo de montaña, en trampa de intercepción de vuelo, 14 a 18 - X- 2006, J. Márquez y J. Asiain cols. ” (1, CC-UAEH). “ Zacualtipán, camino a Tizapán, bosque mesófilo de montaña, 1690 m, N 20 ° 39.076 ’, W 98 ° 36.053 ’, trampa de intercepción de vuelo # 1, 14 a 28 - IV- 2011, J. Márquez col. ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 2 ” (1, CC-UAEH). Same data, except: “ trampa de intercepción de vuelo # 1, 20 - IX a 4 - X- 2011 ” (4, CC-UAEH). Morelos: “ Huitzilac, Derrame del Chichinautzin, bosque de encino-pino, en troncos podridos, 10 - IV- 1995, J. Márquez col. ” (1, MAAS). “ Tepoztlán, 2 km N de Santo Domingo Ocotitlán, bosque de pino-encino, 1800 m, en troncos, 15 - IX- 1999, J. Márquez col. ” (4, MAAS). Querétaro: “ Landa de Matamoros, Sierra Gorda, 1 km E de camino a Tres Lagunas, N 21 º 17 ’ 54.2 ”, W 99 º 10 ’ 26.7 ”, 1960 m, bosque de encino, en hongos de troncos, 10 - IV- 2006, J. Márquez y J. Asiain cols. ” (35, CC-UAEH). “ Landa de Matamoros, Sierra Gorda, 2.5 km hacia Tres Lagunas, N 21 º 17 ’ 55 ”, W 99 º 10 ’ 37.2 ”, 1963 m, bosque de encino-pino, en troncos, 2 - VI- 2007, J. Márquez y J. Asiain cols. ” (7, CC-UAEH). Guatemala: San Marcos: “ 2 km E de Tajomulco, N 15 º 04.99 ’ W 91 º 55.563 ’, 2062 m, bosque mesófilo de montaña perturbado, en hongos de repisa, 23 - XI- 1999, J. Márquez col. ” (6, MAAS). Costa Rica: Alajuela: “ Poasito, N 10 º 9.805 ’ W 84 º 12.32 ’, 1938 m, bosque mesófilo de montaña, en troncos podridos, 17 - II- 2000, J. L. Navarrete col. ” (1, MAAS). Puntarenas: “ Área de Protección El Progreso, Sierra de Talamanca, N 8 º 55.296 ’ W 82 º 47.854 ’, 1535 m, selva alta subperenifolia, fumigación de troncos con hongos, 24 - II- 2000, J. L. Navarrete y J. Márquez cols. ” (1, MAAS).	en	Márquez, Juan, Asiain, Julieta (2022): Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae). Zootaxa 5152 (1): 1-129, DOI: 10.11646/zootaxa.5152.1.1, URL: http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47
