The effects of fungicides on symbiotic microbes in honey bee (Apis mellifera) colonies

Symbiotic relationships between microorganisms and their hosts are widespread in nature, and support fundamentally important processes such as food digestion, metabolism, and disease prevention. In honey bee colonies, microbes play essential roles in food processing and digestion and possibly have many other functions yet to be determined. Honey bees inoculate the pollen they store with microbes which causes it to ferment and be converted to bee bread. Due to the action of the microbes, bee bread contains nutrients that were not in the pollen used to create it. Honey bees are exposed to numerous environmental contaminants when they forage for nectar and pollen. We found fungicides that were sprayed during bloom in almond orchards in the pollen collected by bees. Because fungicides are considered safe to bees, they can be sprayed while plants are in bloom. The purpose of our study was to determine the impact of fungicides on the symbiotic microbes in bee bread. We isolated fungi from stored pollen and exposed them to agricultural fungicides. The fungicides inhibited the growth of the fungi. The effects of fungicides on the nutritional content of bee bread and the physiology of the bees also are being investigated.