High reproductive skew in the Neotropical paper wasp Polistes lanio

Abstract

Reproductive conflicts are expected in societies where nonbreeding helpers retain the ability to produce offspring. Despite potential competition from reproductively capable nestmates in social wasps, egg laying tends to be monopolised by a single or relatively few queens. Genetic studies on reproductive partitioning in Polistes paper wasps suggest high reproductive skew in the genus. Conflict is thought to be minimal due to nestmate relatedness or the possibility of inheriting a reproductive monopoly on a nest; consequently, there are inclusive fitness opportunities for nonreproductive helpers. However, most studies are limited to temperate wasp species. Given the cosmopolitan distribution of Polistes, genetic data on group conflicts are required for a broader range of tropical species to determine whether these trends apply across climatic zones. We examined female reproductive skew in the Neotropical paper wasp Polistes lanio, genotyping a selection of adults and pupae from established post-emergence nests using single-nucleotide polymorphisms (SNPs). SNP-based pedigree analyses indicate a reproductive monopoly held by a single queen, with queen replacement from natal nestmates and evidence of possible multiple mating. Relatedness between pupal offspring was high (r = 0.71). It is likely that high reproductive skew among females is a founding trait of Polistes societies, conserved among species that have spread into new environments from Indomalayan origins.