Researchers from the University of Illinois have finally uncovered a clue to the mystic mating ritual of the honey bee. The scientists have pinned down an odorant receptor that allows male drones to find a queen in flight. The receptor, on the male antennae, can detect an available queen up to 60 meters away.
This is the first time an odorant receptor has been linked to a specific pheromone in honey bees. The findings appear in the Proceedings of the National Academy of Sciences.
The “queen substance,” or “queen retinue pheromone,” was first identified decades ago, but scientists have only recently begun to understand its structure and role in the hive. The pheromone is a primary source of the queen’s authority. It is made up of eight components, one of which, 9-oxo-2-decenoic acid (9-ODA), attracts the drones during mating flights. It also draws workers to the queen and retards their reproductive growth.
Principal investigator Hugh Robertson, a professor of entomology, said the research team pursued the receptor for the queen retinue pheromone because it was the “lowest hanging fruit” of the known honey bee odorant receptors. Robertson was among the research group that last year published the entire honey bee genome, a feat that allowed his lab to identify 170 odorant receptors in honey bees.
Robertson and his colleagues knew that male drones probably had little use for most of these receptors. The drones don’t forage and so do not need to detect the subtle scents of flowers. Their social role within the hive is virtually non-existent. They have only one task: to find and mate with a queen. Once they have accomplished this, they die.