Pollen nutrition affects honey bee stress resistance

The honey bee, Apis, is perhaps the most beneficial insect to humans because most of our fruits and vegetables depend on them for pollination. Yet these iconic insects have been plagued by many types of stresses. This paper reviews many lines of evidence pointing to the importance of pollen nutrition in honey bee health. In laboratory studies that used caged honey bees, poor pollen nutrition led to a reduction of worker bees’ resistance to the microsporidian, Nosema apis, an increase of bee’s sensitivity to pesticides, and an increased titer of bee virus. On the other hand, polyfloral pollen made bees more resistant to stresses by enhancing their immune related enzyme activities. At the colony level, good pollen nutrition increased honey bee’s resistance to Nosema ceranae or the ectoparasitic mite, Varroa destructor. The effects of both transportation and habitat changes on honey bees seem most likely mediated via decreased diversity, or amount, of pollen to the colonies. Pollen nutrition, therefore, might work together with other factors in reducing the bees’ resistance and exacerbate the effects of viruses, pesticides, or parasites, eventually resulting in Colony Collapse Disorder. Besides paying attention to all of these other factors, pollen nutrition should be an important focus in the future for maintaining healthy bee colonies.