A scientific note on the lack of effect of mandible ablation on the synthesis of royal scent by honeybee queens

Abstract

Recently, honeybee colonies in which several mated, egg-laying honeybee queens coexist under freely moving conditions were experimentally obtained mainly by ablating a third to a half of both mandibles of queens to avoid inter-queen rivalry (Zheng et al. 2009a). These colonies functioned normally and were used as supporting units for the faster build-up of productive colonies and for production of royal jelly in China (Zheng et al. 2009b). Observations also revealed that queens with a third to a half of one mandible ablated had normal levels of activity compared to intact queens, but they refrained from engaging in lethal contests (Dietemann et al. 2008). Mandibles are the release site of the mandibular glands pheromone. This pheromone possesses many functions (reviewed in Le Conte and Hefetz 2008), among which is the regulation of reproduction of workers. Since the secretory openings of mandibular glands are located at the inner margin of each mandible between the anterior articulation and the base of the apodeme of the flexor muscle (Snodgrass 1956; Figure 1), the gland’s secretions might be affected by partial mandible ablation. Ablation could block or facilitate the release of the pheromone via feedback mechanisms and could thus influence the synthesis rate of the gland or the proportion of its components. We therefore evaluated the effect of this surgical treatment on the composition of the queen mandibular gland pheromone to determine whether changes in its synthesis could play a role in the experimental establishment of polygyny.