Male terminalia morphology of sixteen species of the Drosophila saltans group Sturtevant (Diptera, Drosophilidae)

Abstract

Male terminalia in insects with internal fertilization evolve more rapidly than other structures. The aedeagus is the most variable structure, making it a valuable diagnostic feature to distinguish species. The saltans group Sturtevant of Drosophila Fall contains sibling species, that can be distinguished by their aedeagi. Here, we revised and illustrated the morphology of the male terminalia of the following species: Drosophila prosaltans Duda, 1927; D. saltans Sturtevant, 1916; D. lusaltans Magalhes, 1962; D. austrosaltans Spassky, 1957; D. septentriosaltans Magalhes, 1962; D. nigrosaltans Magalhes, 1962; D. pseudosaltans Magalhes, 1956; D. sturtevanti Duda, 1927; D. lehrmanae Madi-Ravazzi et al., 2021; D. dacunhai Mouro Bicudo, 1967; D. milleri Magalhes, 1962; D. parasaltans Magalhes, 1956; D. emarginata Sturtevant, 1942; D. neoelliptica Pavan Magalhes in Pavan, 1950; D. neosaltans Pavan Magalhes in Pavan, 1950 and D. neocordata Magalhes, 1956. We found that phallic structures (e.g., the aedeagus) evolve more rapidly than periphallic structures (e.g., epandrium), being completely different among the subgroups and within them. This rapid evolution may be due to the action of sexual selection or to the potential role of those structures in speciation.