THE EFFECTS OF QUEENLESSNESS ON THE MATURATION OF THE HONEY-BEE OLFACTORY SYSTEM

During the first week of adult life the olfactory system of the honey bee undergoes a critical period of maturation [Masson and Arnold, Orga nisation and plasticity of the olfactory system of the honeybee, Apis mellifera, in: Menzel and Mercer (Eds.), Neurobiology and Behaviour of Honeybees. Springer-Verlag, Berlin, 1987, pp. 280-295]. This is accom panied by dramatic increases in the volume of the antennal lobes [Winn ington et al., structural plasticity of identified glomeruli in the an tennal lobes of the adult worker honey bee. J. Comp. Neurol., 365 (199 6) 479-490], centres of the brain that receive direct input from prima ry olfactory receptor neurons housed in the antennae of the bee. Here, we show that during the first 4-6 days of adult life there is a signi ficant increase in the percentage of bees that respond to a conditione d olfactory stimulus after a single conditioning trial and, furthermor e, that the ontogeny of this olfactory learning behaviour is altered s ignificantly if the queen is removed from the colony. The absence of a queen during early adult life also has site-specific effects on the m aturation of the antennal lobes of the brain. These results show for t he first time that the queen's presence in a colony has a significant impact not only on the behaviour of the adult worker honey bee, but al so on the structure of the brain. (C) 1998 Elsevier Science B.V. All r ights reserved.