Revealing male genital morphology in the giant ant genus Dinoponera with geometric morphometrics

Abstract

Genitalia include some of the most complex and morphologically diverse structures in insects, finding extensive use in taxonomy, but ant taxonomy is female biased and knowledge of the males is little explored, potentially depriving ant taxonomy of valuable information. We examine the male genital morphology of six species of Dinoponera and the variation among species and within species is described. We performed geometric morphometric analyses for the penisvalvae and lateropenite of the volsella. The results from the descriptions and statistical analyses show the genitalia offer valuable characters for species delimitation. What is presently known as Dinoponera australis can be differentiated into discrete populations, perhaps some representing cryptic species. The similarities between D. australis and D. snellingi suggest a close relation between them as well as between D. gigantea and D. quadriceps. We conclude that several genital characters, especially those of the penisvalvae, can be used to differentiate the species and might be useful to clarify the taxonomy of Dinoponera.