Diversity of pollen diet and viral infection affect survival and physiology in honey bees

Honey bees are exposed to a variety of environmental stressors that impact their health.  While important individually, these factors likely interact to produce the greatest effects.  Of particular interest is the interaction between nutritional stress and viral infection.  When honey bees are starved of pollen, or receive pollen from a single plant source, their lifespan and immune functions decrease. Viral pathogens, especially Israeli acute paralysis virus (IAPV), have also been implicated in honey bee losses, though neither viruses nor nutrition fully explain this problem.  Thus, the interaction between nutritional deprivation and viral infection is an important question in honey bee health. We have performed experiments at several levels to better understand these factors.  At the bee level, we studied small groups of bees exposed to viruses and variable pollen diets in the laboratory. At the hive level, we scaled these experiments up into small hives, providing similar treatments in semi-field conditions. We also investigated the landscape level, performing a survey of bee hives across Iowa to compare how bee health correlates with landscape use surrounding the hive. Our results underline the complexity of interactions that occur to affect honey bee health and provide new data on how bee nutrition is of extreme importance.