Evolution of worker sterility in honey bees: egg-laying workers express queen-like secretion in Dufour's gland

摘要

Unlike many social insects in which overt conflict over male production may exist between queens and workers, the queen honey bee seems to have almost absolute dominance over male production (Page and Erickson 1988; Visscher 1989, 1996). The evolutionary explanation for this successful domination is that multiple mating by the queen creates a new genetic asymmetry between workers and males in the colony. Consequently, it becomes more profitable to rear brothers rather than nephews, providing a driving force for the evolution of selective elimination of worker-born eggs by other workers in the colony (Woyciechowski and Lomnicki 1987), a phenomenon later termed "worker policing" (Ratnieks 1988). In a later study it was further shown that egg discrimination is pheromonally mediated and that the pheromone source is the queen's Dufour's gland (Ratnieks 1995). Recently, Oldroyd and Ratnieks (2000) reported that anarchistic workers evade policing by laying eggs that are more acceptable than those of normal workers, presumably because they counterfeit the queen-produced egg-marking pheromone. In support of their hypothesis, they cite Katzav-Gozansky et al. (1997a) as follows: