Queen Bee Attracts Workers with Chemical Cocktail
A honey bee queen attracts the retinue of workers that groom and feed her by releasing a complex concoction of at least nine different chemical compounds, report the authors of “New components of the honey bee (Apis mellifera L.) queen retinue pheromone.” Previous research pinpointed the queen’s mandibular glands as the source of a retinue-attracting pheromone dubbed QMP, which consists of five subcomponents. However, worker bees that respond poorly to QMP still attend their queen normally, suggesting that the complete retinue-attracting pheromone includes additional components beyond QMP. In search of these unidentified compounds, Christopher Keeling and colleagues used selective mating to produce bee colonies that responded poorly to synthetic QMP but strongly to extracts from whole queen bees. By comparing the response of these bees to different extracts isolated from various queen bee body parts, the researchers narrowed in on four new compounds: methyl oleate, coniferyl alcohol, hexadecan-1-ol, and linolenic acid. These four compounds, originating from several glandular sources, were not attractive alone or together, but instead acted synergistically with QMP to elicit a heightened response. However, all nine components together elicited a weaker response than whole-queen extracts at higher doses, suggesting that additional components remain to be identified. The authors note that this multiglandular, retinue-attracting blend is one of the most complex pheromones known to induce a single behavior in any organism.
