Revisão dos gêneros de Tachydromiinae (Diptera: Empidoidea, Hybotidae) baseada na análise cladística dos caracteres morfológicos

Abstract

Tachydromiinae are cosmopolitan, small to minute, exclusively predator flies and comprise about 1200 species. The rapid increasing of monotypical genera during the last years, as well as the absence of a formal cladistic relationship hypothesis among the genera encouraged this study, that aimed to increse the knowledge about the cladistic relationship among the genera of Tachydromiinae based on a worldwide survey of exemplars, using morphological characters of adults; consequently, this study aimed to test the generic monophyly, propose a generic arrangement logically consistent with the dicotomic pattern of the cladistic analysis, and provide an identification key to the genera with worldwide approach as a preventive action against the desnecessary generic inflation. The analysis covered 71 morphological characters from males and females, external and internal mouthparts, male and female terminalia, and the exemplars were selected to represent the polymorphies of the group. The parsimony cladistic analysis using implied weighting (4 ≥ k ≥ 8) returned 63 most parsimonious cladograms and supported the actual tribe classification, with Tachydromiini sister group of Drapetini. In Tachydromiinae was obtained the following relationship: Platypalpus + Platypalpus arnaudi + (Afrotachyempis gen. nov. + (Dysaletria + (Tachypeza + (Tachyempis + Tachydromia)))). We could not corroborate the monophyly of Platypalpus including the species formerly in Charadrodromia, and the further genera of Tachydromiini were grouped in a clade sister to the major part of Platypalpus, where Ariasella and Pieltainia were synonymized in Tachydromia, as well as created Afrotachyempis gen. nov. for the Afrotemperate species of Tachyempis. In Drapetini, we obtained the following cladistic relationships: Chaetodromia + (Austrodromia collini + Austrodromia indifferens + (Megagrapha + ((Atodrapetis + Isodrapetis) + (clado Elaphropeza+ + clado Chersodromia+)))), where Austrodromia was found paraphyletic to Megagrapha and had part of its species transferred to this genus. Besides the more plesiomorphic genera (Chaetodromia, Austrodromia, Megagrapha e Isodrapetis), Drapetini was divided into two monophyletic clades: the clade Elaphropeza+ (Elaphropeza + (Heliopeza gen. nov. + (Crossopalpus + Drapetis))), with Elaphropeza divided into two genera, being Heliopeza gen. nov. corresponding to E. (biuncinata) group, and the clade Chersodromia+ (Chersodromia longicornis + (Chersodromia arenaria + Chersodromia beckeri + Chersodromia cana + Chersodromia galapagensis + Chersodromia hirta + Chersodromia incana + (Chersodromia afrosylvatica + (Micrempis + ((Nanodromia + Alodromia) + (Austrodrapetis + (Baeodromia + Stilpon))))))). The species of Chersodromia are involved in a polytomy and the monophyletism of the genus was not supported. Ngaheremyia, Pontodromia and Chersodromia zelandica were grouped into Austrodrapetis due to the apical origino f Radial sector, corroborating some suggestions in literature. In this new concept, the subfamily is summarized in 23 monophyletic genera plus Platypalpus, Austrodromia and Chersodromia. foram congregados à Austrodrapetis mediante a origem apical do setor Radial, corroborando algumas sugestões em literatura. Neste novo conceito, a subfamília é sumarizada em 23 gêneros monofiléticos mais Platypalpus, Austrodromia e Chersodromia.