Reproductivity and relatedness in a communal halictine beeLasioglossum (Chilalictus) hemichalceum

Abstract

The biology of communal species is not well known. Here we report the reproductivity (number of offspring per female) and genetic relatedness forLasioglossum (Chilalictus) hemichalceum, a communal halictine bee. There is a positive Model II regression, with a slope indistinguishable from one, between natural logarithms of the number of offspring and the number of adult females in a colony; indicating that as colony size increases the reproductivity per female does not decrease. This pattern is like that found in one other communal species and unlike that found in a wide variety of eusocial species. Relatedness among adult nestmates, based on two variable loci, is low. For 52 colonies it is about 0.13, and for a subset of 25 reproductively active colonies it was not distinguishable from zero. This indicates that the role of kin selection is minor at best in this highly cooperative, communal species. A review of the relatedness data available for communal groups, both foundress associations and species that are communal throughout their colony cycle, indicates that communal sociality is often but not always associated with low intra colony relatedness.