Examining the causes of differential responses to the queen in drones and workers of the honey bee, Apis mellifera

In honey bees, the social interactions of workers and drones with the queen are largely mediated by the pheromone component, 9-ODA, an attractant. The effects of 9-ODA are developmentally and spatially context dependent, however. Drones show no attraction to the queen while inside a hive, at any age. They also don’t take mating flights outside of the hive before reaching maturity, and even then, only at specific times during the day (Giray and Robinson, 1996). Workers, by contrast, are receptive to the queen soon after emerging; this is when they participate in queen tending and rearing and it is at this time that attraction to the queen and to 9-ODA is strongest (Boch et al., 1975). As workers age and transition from nurses to foragers, exposure and receptivity to the queen decreases. Though we have a good sense of the contextual dependency of the behavioral interactions with the queen in workers and drones, our understanding of the physiological and molecular mechanisms underlying these differential behaviors is not well understood. Here I look at the interaction of 9-ODA with the peripheral nervous system across worker and drone behavioral states and show that levels of the olfactory receptor for 9-ODA, OR11 (Wanner et al., 2007), are higher in young nurses and sexually mature drones, groups which show behavioral receptivity to the queen. Electrophysiological assays were employed to gauge the peripheral nervous system’s sensitivity to 9-ODA across these same groups and to ascertain the relationship between levels of receptor expression and physiological sensitivity to 9-ODA. The findings here may indicate a role for the peripheral nervous system in mediating, in part, the differential behavioral responses to the queen in workers and drones.