1. ^*, Ecology Graduate Group and ^† Department of Entomology, University of California, Davis, California 95616, USA
2. ^‡Present addresses Departments of Organismic and Evolutionary Biology and Anthropology, Harvard University, Cambridge, Massachusetts 02138, USA (PC F ), Department of Zoology NJ15, University of Washington, Seattle, Washington 98195, USA

Abstract

Division of labour among nestmate workers is central to the colonial organization and ecological success of the eusocial Hymenoptera (ants, bees and wasps)¹. Workers characteristically divide labour through (1) ontogenetic changes in individual behaviour^2,3 and (2) inter-individual variation in behavioural repertoire^3,4. On the basis of current evidence, optimization models of colony demography^3,5,6 assume that variation among nestmates in behavioural repertoire arises solely through variation in environmental conditions, such as larval nutrition (inducing size-mediated behavioural differences in many ants)^3,4,7 and adult experience (effecting behavioural differences among morphologically similar nestmates)⁸. A possible genetic component to division of labour, however, has received little study⁹. Yet, the degree of genetic heterogeneity among workers within Hymenopteran colonies is often extremely high¹⁰, a consequence of multiple mating by the queen (polyandry^11,12) and/or the presence of multiple laying t (J B ) queens (polygyny¹³). Here we report evidence of genetically based variation in task performance among nestmate workers in the polyandrous honey bee Apis mellifera L. Such variation may be an important component to division of labour within genetically heterogeneous colonies.