Bittacus brasiliensis Klug, 1836

Machado, Renato Jose Pires, Morelli, Enrique, Heleodoro, Raphael Aquino & Silva, Vitor Cezar Pacheco Da, 2025, First record of the insect order Mecoptera (Hexapoda) from Uruguay, Zootaxa 5665 (4), pp. 577-582 : 578-580

Bittacus brasiliensis Klug, 1836

( Fig. 1 , 2 )

Bittacus brasiliensis : Klug, 1836: 98; Esben-Petersen 1921: 152; Penny & Byers 1979: 367; Willmann 1983: 53; Machado et al. 2009: 36; Machado et al. 2018: 306 (lectotype designation).

Lectotype: female: Museum für Naturkunde, Berlin, Germany: Casapava, Sello (green label)/ cotype (red label)/ 217 (white label)/ 1. (white label)/ Bittacus brasiliensis Klug (white label). See Figure 1b in Machado et al. (2018). Type Locality: Brazil: Rio Grande do Sul: Caçapava do Sul.

Diagnosis. Wing membrane hyaline; forewing apex not falcate; forewing with Sc ending at the level of the first fork of Rs; male epandrium without mesial elongated expansions, and apical internal margin with a lobe bearing black spines.

Redescription. Head ( Fig. 1b ): mostly pale, except for the dark brown gena, apical half of labrum and ocellar triangle; set with pale pubescence, particularly in the vertex; three ocelli, lateral ocelli slightly larger.Antennae long, filiform, pale, with pale pubescence; flagellum generally slightly darker than scape and pedicel. Male maxillary palpi dark brown and broad, and set with elongated black setae.

Thorax ( Fig. 1a–b ): covered with yellowish pubescence. Pronotum brown with the medial area pale. Antepronotum and postpronotum with one long black seta on each lateral margin. Mesonotum and metanotum brown laterally and pale medially; with two long black setae on the anterior half of each segment. Scutella pale, with two long black setae on posterior margin. Pleural region pale.

Legs ( Fig. 1a ): coxae pale; yellowish pubescence slightly longer than on other segments. Trochanter brown. Fore and mid leg with femur and tibia brown, except for the tip of the tibia dark brown, tarsi dark brown. Hind leg with darker brown tibia and tarsi; in general, more robust than anterior legs, but with tarsi shorter, particularly the first and second tarsomeres, which are nearly half the size of their respective counterparts in the fore and mid legs. Legs set with sparse short black setae; tibial spurs long and with the basal half dark brown and the apical half pale; tarsomere V prehensile.

Wings ( Fig. 1f ): narrow with apex rounded. Membrane hyaline, but pterostigma and area near it brown; thyridium present; longitudinal veins brown, covered by short black setae. Forewing costal crossvein varying from zero to two; humeral crossvein present; Sc at the level of Rs first fork; Rs fork not forming a right angle; Rs 1+2 forking before the pterostigma end; Rs 3+4 forking half way through to the level of Sc end and pterostigma; two pterostigmal crossveins; M origin much before to Rs origin; M and Rs first forks at the same level; Cu 1 ending at the level of Rs 3+4 fork; A 1 ending after to Rs origin. One crossvein between Rs 1 and Rs 2, three between Rs 1+2 and Rs 3, two between Rs 3 and Rs 4, three between Rs 4 and M, one between Rs 4 and M 1+2, two between M 1 and M 2, two between M 2 and M 3, one between M 1+2 and M 3+4, one between M 3 and M 4, one between M 4 and Cu 1, one between Cu 1 and Cu 2. Hindwing similar to forewing but shorter.

Abdomen ( Fig. 1a ): shorter than wings, mostly brown, but apical margins of the tergites dark brown, pleura pale. Segments covered by pale pubescence.

Male terminalia ( Fig. 1c–e ): epandrium brown, set with pale setae; in dorsal view, internal margin diverging apically, posterior margin rounded, apical internal margin with an internal lobe set with short thick black setae; in lateral view, slightly shorter than basystilus, dorsal margin mostly straight; posterior margin obliquely truncate and posterodorsal corner rounded. In posterior view bean shaped, with internal margin set with short thick black setae. Cercus about as long as sternite IX, brown, set with pale setae. Basistylus set with long yellowish setae, particularly at the posterior margin, brown with apex pale. Dististylus short, slightly darker than basistylus, with apex rounded, set with long yellowish setae. Penisfilum broad at base, abruptly narrowed medially, tapering towards the apex, curving backwards at the medial region, basal broad region darker than remaining areas.

Female terminalia: with cercus short, brown, set with yellowish setae. Subanal plate and tergite XI brown and set with short yellowish setae. Cercus, subanal plate, and tergite XI ending about at the same level. Gonocoxosternite dark brown, set with yellowish setae, not fused ventrally; in lateral view with a subapical membranous concavity.

Material examined: Uruguay: Artigas, Laureles stream, 25.xi.1959, coll. C. S. Carbonell, P. San Martín, A. Mesa, 1♀ . Cerro Largo, Sarandi de Quebracho , 17.xi.1959, Coll. C. S. Carbonell, A. Mesa. P. San Martin. In a small patch of grass, at the edge of the mountain on the hillside of the hill, 2♀, 6♂ ; Florida, Veinticinco de Agosto , 21. xii. 1963, 1♀ ; Lavalleja, Asperezas de Polanco , 4.xii.1966, Coll. F. Achaval, 1♀ ; Rivera, Lunarejo stream: tributary Gajo del Lunarejo, close to the San Miguel hill, 16.xi.1955, Coll. C. S. Carbonell, rainy day, flying at sunset, by the hillside with tall grass and bushes. 6♀, 4♂ ; same data, except: Lunarejo stream: Cuchilla Negra, 4♀, 3♂ ; same data, except, Cerros Blancos , 23.xi.1959, Coll. C. S. Carbonell, A. Mesa, P. San Martin, 1♀ ; Km 478, Ruta 5 , 5.xii.1966, Coll. C. S. Carbonell, A. Mesa, P. San Martin, under rock, preserved in alcohol, 1♂, (The label says “Km 478 Ruta, Tacuarembó”; however, route 5 is the most probable route due to its size, and the correct department should be Rivera, because km 478 is not in Tacuarembó) ; Tacuarembó, Gruta de los Helechos , 9.xi.1954, Coll. A. Silvera, V. Carbonell, 1♂ .

Figures

FIGURE 1. Bittacus brasiliensis Klug, male. A. Habitus; B. Head, frontal view, C. Terminalia lateral view, D. Terminalia, dorsal view, E. Terminalia, posterior view, F. Anterior wing. Bar scale: 2mm. Photos taken by V. C. Pacheco da Silva.

FIGURE 2. Geographical records of Bittacus brasiliensis Klug (new records in Uruguay and older records from Caçapava do Sul, Rio Grande do Sul, Brazil and Loreto, Misiones, Argentina) and B. zelichi Williner (only record from El Palmar, Entre Ríos, Argentina).