In the honey bee (Apis mellifera), young workers usually perform tasks in the nest while older workers forage in the field. The behavioral shift from nest-task to foraging activity is accompanied by physiological and sensory changes so that foragers can be characterized by a higher juvenile hormone (JH) level, a lower vitellogenin protein titer, and an increased responsiveness to water and sucrose stimuli. JH was hypothesized to be the key mediator of behavioral development, physiology, and sensory sensitivity in honey bee workers. Recent research, however, has shown that JH is controlled by the hemolymph vitellogenin level, which implies that the fat body specific vitellogenin gene can be a key regulator of behavioral change. Here, we show that downregulation of vitellogenin activity by RNA interference (RNAi) causes an increase in the gustatory responsiveness of worker bees. Our observations suggest that vitellogenin is an important regulator of long-term changes in honey bee behavior.
