BEHAVIORAL, PHYSIOLOGICAL AND MOLECULAR EFFECTS OF MULTIPLE FACTORS IMPACTING HONEY BEE HEALTH

Stress can have profound effects on behavior and physiology. The importance of stressors in agricultural systems has been highlighted in recent reports of "Colony Collapse Disorder", in which managed honey bee colonies undergo rapid and massive population declines. CCD is likely caused by a combination of stressors: pests (ie Varroa mites), pathogens, environmental toxins (including the acaricides used to control Varroa), and poor nutrition, possibly due to the use of artificial diets and monoculture cropping systems. However, in order to fully understand how different stressors undermine the health of social insects, it is necessary to examine effects on individuals and across the complete social structure. We will examine the effects of four stressors (mating number, nutrition, virus infection, and environmental toxins) on queen and worker physiology, behavior, and social interactions. The research outlined in this proposal is highly multidisciplinary and integrative, seamlessly combining apiculture, behavioral ecology, chemical ecology and genomic analyses. It will dramatically improve our understanding of the molecular, physiological and behavioral effects of stress responses in insects, in particular social insects, have significant impacts on the management of honey bee populations for agriculture, and serve as an outstanding vehicle for education and outreach. Our studies will allow us to determine if a broad array of stressors has similar or specific impacts on behavior, physiology, social communication, gene expression, and gene networks in honey bees, and thus will provide an integrative understanding of the effects of stress. Honey bees are an excellent model system for these studies because this species has large genomic resources, complex social behavior, and a number of naturally occurring stressors which are critical for both managed and unmanaged bee populations. Futhermore, honey bees are the most important pollinator of almost 100 crops and orchards grown in the U.S., and they are a producer of honey and other hive products. Our studies will highlight the importance of modifying current management practices in order to improve honey bee heath, but may also provide new diagnostic tools or methodology to ameliorate the effects of the stressor. For example, if there is a chemical "stress signature" that can be observed in the blend of volatile organic compounds of the queen, queens can be nondestructively surveyed to monitor the health of the colony. If there are specific molecular stress signatures revealed by the microarray analysis, workers can be sampled to monitor colony health or perform epidemiological analyses. Finally, if poor queen pheromone production negatively impacts worker behavior and physiology, supplements can be developed to maintain colony organization and structure until the queen can be replaced.