POLYGYNY AND THE EVOLUTION OF SOCIAL BEHAVIOR IN WASPS

Abstract

A survey of the group composition of primitively social (nest sharing, casteless) wasps reveals that virtually all are polygynous (have more than one egg-laying female per nest), and that life in groups of genetic relatives is common (except possibly in some species showing only occasional or short-term nest sharing). Furthermore, incipient and well developed worker castes are present in polygynous wasp societies. There fore polygynous family groups, rather than groups, matrifilial monogynous groups, or groups of non-relatives, have probably been a major setting for the evolution of a worker caste in wasps. General kin selection and mutualism hypotheses are more applicable as explanations for helping (worker) behavior in such groups than are the haplodiploidy or maternal control hypotheses. Long-term monogyny, which is required by the latter two hypotheses, probably more often followed rather than preceded the advent of sterile castes in the evolution of the social wasps. A polyg ynous family hypothesis is proposed as an alternative to the subsocial and semisocial hypotheses for the evolution of insect sociality.