Tabanus callosus Macquart
(Figures 7 A–D, 8A–D, 31)
Tabanus callosus Macquart, 1848: 171 (1848: 11); Walker, 1854: 200 (BMNH spp.; Hunter, 1901: 140 (cat.); Kertész, 1908: 232 (cat.); Kröber, 1933: 342 (taxonomy), 1934: 292 (cat.); Fairchild, 1942b: 162, pl. 1, fig. 4 (taxonomy), 1956: 12 (syn.); Barretto, 1957: 86 (Guiana spp.); Philip, 1960: 82 (Peru spp.); Fairchild, 1970: 840 (French Guiana spp.), 1971: 103 (cat.; as syn. of trivittatus Fabricius, 1805), 1976: 246, fig. 4 (rev.); Moucha, 1976: 97, 148 (cat.; as syn. of trivittatus Fabricius, 1805); Wilkerson & Fairchild, 1985: 51 (Peru spp.); Rafael et al., 1991: 361 (Roraima spp.); Henriques & Gorayeb, 1993: 19 (MPEG spp.); Fairchild & Burger, 1994: 132 (cat.); Henriques, 1997: 88 (INPA spp.); Henriques & Rafael, 1999: 215 (distr.); Henriques, 2004: 148 (habitat); Coscarón & Papavero, 2009: 125 (cat.); Wolff & Miranda-Esquivel, 2016: 280 (cat.); Henriques, 2016: 178 (AMNH spp.); Krolow et al., 2017: 104 (French Guiana spp.).
Diagnosis. Style subequal to postpedicel, never less than half its length. Scutum and scutellum blackish with grey pruinescence, notopleuron concolorous with scutum and with long black hairs. All coxae and femora black, the former with gray pruinescence Abdomen with three abdominal stripes, the middorsal reaching tergite 6, dorsolateral reaching tergite 4, sometimes with faint indications at 5. Abdomen clearly banded ventrally.
Comments. This species has great resemblance with T. trivittatus . Both species show a uniform morphology and similar body sizes ( T. trivittatus ranges from 9 to 16 mm, while T. callosus ranges from 8 to 14 mm). The major difference between the species is the antennae, where, the postpedicel (basal plate) in T. callosus is short and in T. trivittatus the postpedicel is long, usually twice the style length. In addition, the postpedicel tooth angle is closer to the base in T. trivittatus . Some specimens of T. callosus seem to possess intermediate states between the two species. There is also great variation between the two in regards to sternite 8 of female genitalia (Fig. 29 A – F). We also observed morphological difference in the males. The male postpedicel of T. callosus is shorter than T. trivittatus (Figs. 8D and 26D). In addition, the subcallus is bare and inflated at ventral region in the male of T. callosus (Fig. 8C, D), but pruinescent and flat in the male of T. trivittatus (Fig. 26C, D). The differences observed in the males corroborate the hypothesis that these are two different species.
Material examined. Large series of INPA and MPEG collections with records distributed through the Amazon Basin. BRASIL, Amazonas BR 119 , km. 275; Coari; Novo Airão; Parque Nacional do Jaú (50 ♀ and 6 ♂ INPA); Amazonas, São Gabriel da Cachoeira; Barcelos, Manaus; Roraima, Ilha de Maraca; Rondônia, Ouro Preto do Oeste. COLOMBIA, Vaupes (43 ♀ MPEG) .