Morphometric characters in the taxonomic recognition of the species of Dolichopus pennatus group (Diptera: Dolichopodidae)

Sexually dimorphic structures (ornaments) on the legs are important diagnostic features for Dolichopus males, whereas females of those males are often morphologically similar and their species diagnostics is difficult. To assessing the relevance and feasibility of setting diagnostic characters for five sister species of the genus Dolichopus Latreille, 1796 (D. argyrotarsis, D. lineaticornis, D. pennatus, D. popularis, D. subpennatus) analysis of morphometric trait was used: comparison of wing shape by methods of geometric morphometry, as well as comparison of the ratios of the leg segments lengths. Comparative analysis of morphometric characters with molecular data made it possible to study the phylogenetic signal of male leg ornaments. It was shown for Dolichopus species, that modifications of the males middle legs occurred independently several times in the genus. In addition, the evolutionary pattern in the formation of similar ornaments was also associated with changes in the morphometric features of the legs and wings. Based on wing and legs morphometry, new diagnostic characters were proposed for females of the studied species group.