Hymenopterans generally exhibit a haplo-diploid sex determination mechanism, in which females are produced by sexual reproduction and are diploid and males are produced parthenogenetically and are haploid. In a small number of ant species, workers are able to produce diploid female offspring parthenogenetically from unfertilized eggs, which is termed thelytoky. One of these species, the ponerine ant Platythyrea punctata, is of peculiar interest, because it has been found to have both thelytokous and sexual colonies, which makes it an interesting model system to investigate population structures, colony relatedness patterns and behavioral colony performance that may give new insights on the evolution of thelytoky in social Hymenoptera. The aim of this thesis was to investigate consequences of thelytoky on the genetic population and colony structures and behavioral performance within colonies. By combining genetic and ethological studies, I analyzed the geographic range of thelytokous and sexual populations, the mechanisms underlying thelytoky and male production, as well as other aspects of behavioral performance in social insect colonies with clonal structures
