Taxonomy and phylogeny of the genera Gymnocnemia Schneider, 1845, and Megistopus Rambur, 1842, with remarks on the systematization of the tribe Nemoleontini (Neuroptera, Myrmeleontidae)

The delineation of antlion genera has often been based on morphological characters not tested in a phylogenetic context, thus seriously impairing the study of systematics of the family Myrmeleontidae. Nebulous generic limits also impede the taxonomy and study of the affinities of closely related species. As a case study, the generic placement of Megistopus mirabilis Hölzel, 1980, was based on a single leg character. To test the position of this species, the reciprocal relationships of the members of the genera Gymnocnemia Schneider, 1845, and Megistopus Rambur, 1842 were investigated, using a morphology-based phylogenetic analysis. This approach demonstrated that M. mirabilis should actually be assigned to the genus Gymnocnemia, as G. mirabilis comb. n. This analysis also supports the subdivision of the tribe Nemoleontini in two subclades based on morphology of male and female genitalia. A new characterisation of these genera is provided, as well as a redescription of the very rare G. mirabilis and the poorly investigated Megistopus lucasi (Navás, 1912). An updated identification key to the members of the genera Gymnocnemia and Megistopus is presented.