Multiple mating and supercoloniality in Cataglyphis desert ants

Abstract

In social organisms, the breeding system corresponds to the number of breeders in a group, their genetic relationships, and the distribution of reproduction among them. Recent, genetically based studies suggest an amazing array of breeding system and reproductive strategies in desert ants of the genus Cataglyphis. Using highly polymorphic DNA microsatellites, we performed a detailed analysis of the breeding system and population genetic structure of two Cataglyphis species belonging to the same phylogenetic group: C.niger and C.savignyi. Our results show that both species present very different breeding systems. C.savignyi colonies are headed by a single queen and populations are multicolonial. Remarkably, queens show one of the highest mating frequency reported in ants (Mp=9.25). Workers can reproduce by both arrhenotokous and thelytokous parthenogenesis. By contrast, colonies of C.niger are headed by several, multiply mated queens (Mp=5.17), and they are organized in supercolonial populations made of numerous interconnected nests. Workers lay arrhenotokous eggs only. These results illustrate the high variability in the socio-genetic organization that evolved in desert ants of the genus Cataglyphis. © 2011 The Linnean Society of London.