Pheromones of the Honeybee: Biological Studies of the Mandibular Gland Secretion of the Queen

SUMMARYSeveral substances present in heads of queen honeybees were tested as sex attractants for drones and as stabilizers of the swarm cluster. The experiments showed that the whole of the odour of a queen that attracts drones is produced in her mandibular glands, and that it can be accounted for by 9-oxo- decenoic acid alone. Another pheromone, 9-hydroxydecenoic acid, is slightly attractive to drones; it is responsible for stabilizing swarm clusters. New evidence indicates that few, if any, drones are attracted from long distances by queens, and that the wind speed influences both the number of drones flying and the height at which they fly. Because a drone's visual acuity is small, he must get within 1 m. of a queen before he can see her. Her scent enables him to do this. It is, however, most unlikely that he follows a scent gradient, and an alternative method of using a queen's scent to find her is discussed.Drones appeared to be distributed uniformly around their hives, their numbers decreasing as distance from the hive increased. Few ventured more than 3 km. from their hives in the present experiments; they were found up to 800 m. out at sea. No evidence was obtained that drones normally congregate in particular places, and it is considered unlikely that they do so.