Is the Phasmatodea male genitalia useful for systematics? A case study in Creoxylus and Prexaspes (Insecta: Phasmatodea) from the Brazilian Amazon Basin

Abstract

The male genitalia have been neglected in Phasmatodea studies over the years. There are few works describing and illustrating this organ and no studies demonstrating its usage. Concerned by this matter, this paper aimed to investigate whether the male genitalia of Phasmatodea is useful for systematics. First, by describing a new species of Creoxylus Audinet-Serville (Creoxylusduckei sp. nov.) and including the description of its male genitalia, along with the differentiation from the male genitalia of the know species Creoxylusspinosus (Fabricius). By comparing these two genitalia, the first case of chirality in Phasmatodea was reported. Secondly, by describing the genitalia of two Prexaspes Stål species (Prexaspes viridipes Stål and another identified to genus level) and making the differentiation between them. Finally, by comparing all four described genitalia. Results showed that the male genitalia are useful to differentiation and identification of species/genera. It is discussed what knowledge can be drawn from these genitalia descriptions in terms of phylogeny of Xerosomatinae and Phasmatodea as a whole, as well as homologies with previous literature.