Ruptor, Żyła & Bogri & Hansen & ShaW & Kypke & Solodovnikov, 2022

Żyła, Dagmara, Bogri, Amalia, Hansen, Aslak Kappel, ShaW, Josh Jenkins, Kypke, Janina & Solodovnikov, AleXey, 2022, A New Termitophilous Genus of Paederinae Rove Beetles (Coleoptera, Staphylinidae) from the Neotropics and Its Phylogenetic Position, Neotropical Entomology 51 (2), pp. 282-291 : 285-287

publication ID	https://doi.org/10.1007/s13744-022-00946-x
DOI	https://doi.org/10.5281/zenodo.15578250
persistent identifier	https://treatment.plazi.org/id/E2506715-230A-FF81-FF53-04D3FB9C8F89
treatment provided by	Felipe
scientific name	Ruptor
status	gen. nov.

Treatment

Genus Ruptor View in CoL gen. nov.

Type species: Ruptor cordatus sp. nov.

Diagnosis.

Ruptor gen. nov. ( Figs. 3 View Fig and 4a View Fig ) can be recognised among all Paederinae by the following combination of characters: compact, dorso-ventrally flattened body with dense even cover of setiferous punctures with short pale setae; trapezoid-shaped head with broad frontal area, pronounced posterior angles and small notch on straight posterior margin of head above moderately narrow (ca. 1/3 of head width) neck; in maxillary palps penultimate (third) palpomere slightly longer and wider than second, apical (fourth) palpomere small and acicular; strongly transverse pronotum and notably shortened antennae and legs; protarsi wide, protarsomere 4 simple, not bilobed; protibial combs placed longitudinally (Supplementary Fig. 1a View Fig ); ctenidium present only on posterior side of hind tibia (Supplementary Fig. 1b View Fig ); aedeagus without parameres.

Description.

Medium size beetle (total body length ca. 5 mm); body robust and compact, somewhat flattened; body surface with dense but fine irregular punctation. Appendages shortened and robust.

Head trapezoidal, wider than long, widest in posterior part, with distinct posterior angles, tapering towards smooth anterior angles. Antennal insertions and labrum concealed under bulging frons, not visible from above ( Fig. 3a, b View Fig ). Antennae inserted near anterior margin of eye ( Fig. 4a View Fig ), short, slightly pectinate, reaching anterior margin of pronotum. All antennomeres slightly widened apically, without tomentose pubescence, with smaller pale setae all over surface and few longer and bigger setae around apex of antennomere; stem between antennomeres not visible ( Fig. 4a–c View Fig ). Strongly transverse labrum almost covering closed mandibles from above, its anterior margin straight, not notched or dentate ( Fig. 4a View Fig ), highly sclerotised, with multiple, evenly distributed setae. Mandibles short and stout, without ridges, with prostheca extending from base of mandible to first tooth. Left mandible with two teeth; right mandible with three teeth, first one distinctly smaller than next two ( Fig. 4d View Fig ). Maxillae ( Fig. 4a View Fig ): palpomere 1 short, approximately half of length of maxillary palpomere 2, bearing single seta; maxillary palpomere 2 short, expanded towards apex, with few strong and long setae; maxillary palpomere 3 expanded towards apex with denser setation; palpomere 4 (apical) glabrous and acicular, around 1/4 of palpomere 3 length, thin, 1/3 of width of palpomere 3. Labium ( Fig. 4a View Fig ): palpomere 1 widest apically, slightly thinner than palpomere 2; palpomere 2 elongate, widest at middle, slightly longer than palpomere 1, bearing three setae; palpomere 3 (apical) acicular, with few setae, slightly more than half of length of palpomere 2; mentum transverse, slightly concave along anterior margin; submentum with pair of setae; ligula bilobed. Gular sutures widely separated, gula wider in apical and basal portion ( Fig. 4a View Fig ). Eyes of moderate size, without setae between ommatidia, temples 1.5 × longer than eyes. Neck distinct; slightly more than 1/3 of head width.

Prothorax ( Fig. 4b View Fig ) distinctly transverse, widest just anteriad of middle; superior marginal line of pronotum deflexed under its anterior angles, reaching prosternum, not meeting with inferior marginal line; pronotal hypomera broad forming weak postcoxal process; prosternal suture well developed; basisternum with one pair of large macrosetae; furcasternum long (exceeding tip of postcoxal process), narrowly pointed posteriad, with sharp longitudinal carina in its posterior part; thoracic spiracles without distinct perithremes. Elytra without epipleural ridge. Mesoscutellum glabrous with apical third punctate and setose; obtusely pointed apically, with one transversal scutellar ridge before middle of scutellum length. Hind wings fully developed. Mesosternum (mesoventrite) ( Fig. 4c View Fig ) without longitudinal carina; mesocoxal cavities contiguous, mesosternal (mesoventrital) process acutely pointed. Metathorax ( Fig. 4c View Fig ) well developed. All legs relatively short, with broad, enlarged femora; protibia with two large spines at apical margin and two longitudinal combs of setae. Protarsi ( Fig. 3c View Fig ) enlarged in both sexes, protarsomeres 1 to 4 transverse, with adhesive spatulate setae ventrally, protarsomere 3 slightly bilobed. Mesoand metatarsi ( Fig. 4c View Fig ) same in shape, without adhesive setae ventrally; their tarsomeres 1 and 2 equal in length, tarsomere 5 about as long as tarsomeres 2 to 4 combined. One pair of empodial setae on each tarsus, equal or slightly shorter than claws. Hind tibia with ctenidium on posterior side.

Abdomen widest at segment V; segments III to VII with one pair of paratergites on each side; posterior margin of tergites II to VI with fringe of setae; apical margin of tergite VII with palisade fringe. Sternite III with transverse suture acutely pointed medially. Male: sternite VIII with slight medial emargination ( Fig. 4e View Fig ), tergite VIII truncate ( Fig. 4f View Fig ), with usual setation; sternite IX symmetrical ( Fig. 4g View Fig ); lateral tergal sclerites IX fused in one piece without any sutures apically embracing small tergite X ( Fig. 4h View Fig ); aedeagus symmetrical, without parameres ( Fig. 3d, e View Fig ). Female: sternite VIII apically without emargination; lateral tergal sclerites IX and tergite X as in male ( Fig. 4h View Fig ); sternite IX consisting of pair of weakly sclerotised basal and pair of stronger sclerotised apical gonocoxites ( Fig. 4i View Fig ).

For distribution and bionomics see below species description.

Comparison.

Ruptor gen. nov. is rather distinct among all known genera of Paederinae , including specialised termitophilous and myrmecophilous forms ( Fig. 5 View Fig ), by its habitus alone. Its compact dorso-ventrally flattened body with short appendages, lack of tuberculose sculpture or carinae on forebody, and head with sharp posterior angles (in dorsal view) combined with transverse pronotum easily tell it apart from other, often poorly known, inquiline (or presumably so) Lathrobiini incertae sedis genera, namely Bolbophites Fauvel, 1904 , Ecitobium Wasmann, 1923 , Ecitonides Wasmann, 1894 ( Fig. 5a View Fig ), Ecitosaurus Fischer, 1943 , ( Fig. 5b View Fig ) Ecitotropis Borgmeier, 1936 , Labidophites Borgmeier, 1956 , Mimophites Fauvel, 1904 ( Fig. 5c View Fig ), Synecitonides Reichensperger, 1936 ( Fig. 5d View Fig ) and Monista Sharp, 1876 ( Fig. 5e View Fig ). The new genus superficially resembles some species of the Neotropical Lathrobiini genera Attaxenus Wasmann, 1925 , Paederopsis Wasmann, 1912 or especially Dacnochilus LeConte, 1861 , which presumably belong to the recently discovered Pseudolathra - Cylindroxystina lineage ( Żyła et al. 2021). Within Dacnochilus , a widespread Neotropical genus that occasionally occurs in nests of termites and ants, Ruptor especially resembles D. atrus Jiménez-Sánchez & Galián, 2013 [correct masculine form of the species name should be ater], D. compactus (Casey, 1905) , D. horridulus (Casey, 1905) , D. nahuiollinae Jiménez-Sánchez & Galián, 2013 , D. newtoni Jiménez-Sánchez & Galián, 2013 , or D. zaragozae Jiménez-Sánchez & Galián, 2013 . However, it readily differs from them by a somewhat rugose (not glabrous) disc of head and pronotum, by the presence of ctenidium only on the posterior side of hind tibia, as well as by the longitudinal placement of the protibial combs. Also, Ruptor may distantly resemble members of the subgenus Eurysunius Reitter, 1909 of the genus Astenus ( Astenina ). It differs from all Astenina at least by its simple not bilobed protarsomere 4, by its prosternum not being expanded under the front coxae and not fused with the pronotal hypomera, and by its short and stout mandibles. The new genus differs from all myrmecoand termitophilous Pinophilini and Paederini by having the typical for Lathrobiini small and unmodified apical (fourth) maxillary palpomere; it differs from the myrmecophilous members of Scopaeina by its larger labrum and lack of trichobothrium on the head; it differs from myrmecophilous Stilicina by the wider neck and the prosternum not being expanded under the front coxae and not being fused with the pronotal hypomera.

Etymology: The genus name is a Latin noun of masculine gender meaning burglar or housebreaker. It refers to the social parasitism biology of this taxon which was found in the termite’s ‘house’.