The paralobe: A new diagnostic and synapomorphic character for the genera Paulipalpina Gnaspini & Peck, 1996 and Parapaulipalpina Gnaspini, 1996 (Leiodidae: Cholevinae: Ptomaphagini)

Abstract

In insect taxa with homogeneous external morphology, genital structures often emerge as essential traits for interspecific differentiation. In the tribe Ptomaphagini (Coleoptera, Leiodidae, Cholevinae), precise identification often depends on analyzing the male genital morphology, even at the genus level. Here, we present a new character for diagnosing the genera Paulipalpina Gnaspini & Peck, 1996 and Parapaulipalpina Gnaspini, 1996. This feature, which we dub ‘paralobe’, is a projection arising from the internal surface of the right lobe of the aedeagal apex. Based on its absence in other beetles, including other Ptomaphagini, we recognize it as a putative synapomorphy for those genera. The recognition of this previously overlooked structure adds important information for understanding the sequence of changes that occurred in the male genitalia among the genera of Ptomaphagini.