The biology of the Cape honey bee, Apis mellifera capensis (Hymenoptera: Apidae) : a review of thelytoky and its influence on social parasitism and worker reproduction

Abstract

Cohesion in social insect colonies is maintained by use of chemical signals produced by the queen, workers, and brood. In honey bees in particular, signals from the queen and brood are crucial for the regulation of reproductive division of labor, ensuring that the only reproductive female individual in the colony is the queen, whereas the workers remain reproductively sterile. However, even given this strict level of control, workers can, in principle, activate their ovaries and lay eggs. Although much is known about the behavioral and physiological traits that accompany the switch from worker sterility to being reproductively active, much less is known regarding the molecular changes that accompany this switch. This review will explore what is known about the genes and molecular pathways involved in the making of laying workers/false queens in the Cape honey bee, Apis mellifera capensis Eschscholtz, through an analysis of the basis for thelytoky in this subspecies, the exocrine glandular chemistry of reproductively dominant workers and what is known about the biosynthesis of their pheromone components. This review will contribute to our understanding of the genetic regulation of thelytoky and the molecular mechanisms that govern reproductive division of labor in honey bees and provide generalizations that may be applicable to other social hymenoptera using this evolutionary fascinating example of worker reproduction.