Thelytokous parthenogenesis and the heterogeneous decay of mating behaviours in a bushcricket (Orthopterida)

Abstract

Abstract Parthenogenesis in bushcrickets has an incidence of less than 1%. In the diploid bushcricket Poecilimon intermedius, rearing indicates obligate,thelytokous parthenogenesis. Antibiotic treatment of P. intermedius was not effective in restoring male production, and negative results fromPCR screening excluded feminizing endosymbionts, such as Wolbachia, as a reason for the lack of males. The geographical range ofP. intermedius follows the general pattern of geographical parthenogenesis, being more northerly and much larger than in the sexual relatives.This is a rare example of geographical parthenogenesis that is not attributable to endosymbiont infection or polyploidy. Females of theparthenogenetic species show differential decay of mating-related behaviour. While interspecific matings were readily achieved in captivity, withspermatophores being transferred and sperm successfully entering the females, the parthenogenetic females exhibit no phonotaxis towards singingmales.Key words: Asexual – geographical parthenogenesis – Wolbachia – antibiotic treatment – vestigialization – acoustic communication