Chemical signals of queens in kin recognition of honeybees,Apis mellifera L.

Summary The volatile signals of live queens as well as head and tergite extracts were analyzed by capillary gas chromatography. Multivariate analysis revealed a significant decrease in the variability of the volatile signals of queens the more closely related they were. Though extracts of the tergal glands showed the same phenomenon, head extracts of closely related queens had no significantly reduced variabilities compared to extracts of unrelated queens. Workers, tested in a metabolic bioassay, could not discriminate among head extracts of related and unrelated queens. Therefore the classical queen substance and the semiochemicals of the mandibular glands are unlikely to be used as kin recognition labels by the workers. Workers could, however, discriminate among the odours of tergite extracts and the volatile signals of queens, indicating that the signal of the tergal gland secretions is a possible source for kin recognition labels which the mandibular gland secretions are not. Furthermore the results show that learning is strongly involved in the kin recognition system of honeybees.