When does cheating pay? worker reproductive parasitism in honeybees

Abstract

In all societies, cooperation between members is necessary to allow the society to function smoothly. However, as the interests of individuals rarely overlap completely, all societies contain members that act selfishly at the expense of the greater entity. Thus, policing mechanisms are generally required in order to maintain cohesion within the society. In social insects, conflict between individuals and the society are often reproductive in nature. Kin selection theory predicts that in haplo-diploid, polyandrous species such as honeybees, workers should largely refrain from producing their own offspring, as the workers collectively have higher inclusive fitness if they rear the sons of their mother, the queen. However, opportunities for personal reproduction at the expense of colony-level fitness are often exploited by individual workers, a phenomenon known as worker reproductive parasitism (WRP). This has led to the evolution of worker ‘policing’, in which workers selectively destroy worker-laid eggs that would otherwise be reared at the colony’s expense. In my PhD, I have investigated WRP in both the Western honeybee Apis mellifera, and the Asian hive bee A. cerana. The major theme of my research has been to elucidate the circumstances that afford opportunities for potential reproductive parasites to evade worker policing. This research is significant, as it yields insights into the conflicting selective forces that lead to the formation of societies, the selfish behaviour of the individuals that comprise them and how this behaviour is controlled. These insights are applicable to all social species, including humans.