Estudo das espécies do grupo tabanus sorbillans wiedemann 1928 (diptera: tabanidae)

Abstract

The flies popularly known as "horseflies" are tabanids belonging to one of the largest orders of insects, Diptera isuborder Brachycera). According to Fairchild and Burger (1994), the Tabanidae family is composed of 4,300 species distributed in 137 genera. Of these 1172 species distributed in 65 genera have records for the Neotropics. Fairchild (1969) also proposed a division of the genus Tabanus into groups that present differences in characters of possible phylogenetic interest: T. xenorhynchus, T. nebulosus, T. pellucidus, T. fortis, T. indecisas, and some species that do not fit into the other groups: T. duckei, T. humboldti, T. aurora. There is a need to organize morphologically the related species of the Tabanus sorbillans group. The present work aims to study the species related to T. sorbillans and treat them as the same group. The studies were based on specimens from the entomological collection of the Museu Paraense Emílio Goeldi (Belém, Pará), and the specimens were studied for their morphology under a stereoscopic microscope. The acquired data were organized in spreadsheets of the "Excel" program. Five species of the group T.sorbilans, T.antarcticus, T. albocirculus, T. rubripes, T.sorbillans and Tabanus sp.n are being analyzed. Head characters were analyzed: antenna, eyes, vertex, forehead, subcallus, gena, beard, frontoclypeus, palpus, proboscis. Thorax: wings, mesonotum, prescutellum, scutellum. Abdomen: tergites, sternites. Tabanus sp n. differs from the other species by having hyaline wings, and is endemic to northeastern Pará; T. antarcticus has the least intraspecific variation, except for the apex; T. albocirculus, does not occur in Brazil and has a vast tuft of black bristles on the pre-scutellum and scutellum, surrounded by white hairs, resembling a circle. T.rubripes presented the longest body length with an average of 15.1 mm. T.sorbillans presented the mean for greatest wing width of 4 mm. Other measurements are being made: basal plate length, anterior tibia length, second palpus length, wing length, forehead apex width, forehead base width, indices, forehead height, antennal insertion distinction and eye banding design, which will be presented in the final report.