The Vibration Signal and Juvenile Hormone Titers in Worker Honeybees, Apis mellifera

We examined the association between the vibration signal and juvenile hormone (JH) titers of honeybees by comparing vibrated recipients and nonvibrated control workers that had been matched for age, colony of origin, and time of collection. Recipients collected at the moment they received vibration signals (0-min bees) did not have higher JH titers compared with controls, which suggests that a worker’s initial JH level did not influence its likelihood of receiving signals. In contrast, JH titers in workers collected 15–30 min after receiving vibration signals were slightly, but significantly higher than those of controls monitored for the same amount of time. These trends were consistent among colonies, despite the fact that we collected different age ranges of workers and observed pronounced variation in JH titers within and between the 0and 15–30min groups of bees. Thus, over a broad age range of workers the vibration signal may contribute to elevated JH levels, and this effect does not occur because recipients have higher titers at the moment they receive signals. Because JH affects response thresholds in honeybees, increased titers elicited by the vibration signal may allow the signal to influence the performance of a variety of tasks in different worker age groups. Correspondence: S. S. Schneider, Department of Biology, University of North Carolina, Charlotte, NC 28223, USA. E-mail: [email protected]