Amazons Are Back: Absence of Males in a Praying Mantis from Uruguayan Savannas

Abstract

With a broad distribution throughout South America, Brunneria subaptera (Saussure) (Coptopterygidae) is the most abundant praying mantis species in Uruguay, mostly associated with grassland vegetation. Their body coloration can vary between green or brown sepia. The recent catalog of Uruguayan mantids showed that all specimens of B. subaptera from the collections in Uruguay were females, suggesting an absence of males in natural populations. The aim of this study was to determine the occurrence of female-only populations of B. subaptera in Uruguay. Moreover, we analyzed the genetic variation and estimated the time of the most recent common ancestor of the species. We performed bimonthly samplings in two localities in Uruguay for 1 year and we sexed the individuals. We extracted DNA from the abdominal tissue of adult females and sequenced a fragment of the mitochondrial cox1 gene to assess the genetic diversity and to estimate diversification times. We did not find any males in either of the studied localities. The age estimates revealed a recent origin of the species (2.33 Ma), and there was no genetic differentiation between the individuals from Uruguayan localities. This absence of males of B. subaptera documented in the sampled locations suggests that the species reproduces by thelytokous parthenogenesis. This study opens promising venues for future research into reproductive strategies and polymorphism in South-American praying mantises that inhabit one of the largest areas of grasslands in the world, currently under dramatic deterioration and reduction.