The first two cases of antisymmetry in the male genitalia of Phasmatodea reveal a new species of Isagoras Stål, 1875 (Phasmatodea: Pseudophasmatidae: Xerosomatinae) from the Brazilian Atlantic Forest

Abstract

Asymmetry is a common phenom among invertebrates. A consequence of this phenom is the rise of chiral forms (or enantiomorphs), which are structures that are mirror images of each other. The asymmetry can be divided into two: directional asymmetry, when only one of the enantiomorphs exists in nature, and antisymmetry, when both chiral forms exist in nature in equal frequencies, a much rarer phenom than the prior. In this paper, I describe the unknown male and redescribe the female of Isagoras paxillus (Westwood) and a new species of Isagoras Stål from the Brazilian Atlantic Forest, Isagoras sobrali sp. nov. (based on males from Rio Grande do Norte: Natal). Furthermore, I also describe the first case of antisymmetry in Phasmatodea in these two species and discuss the relevance of this finding within a morphological, behavioral, and systematic context.