The U.S. Department of Agriculture (USDA) has released a report from the October 2012 National Stakeholders Conference on Honey Bee Health assessing causes of honey bee colony collapse. Stating that the views expressed are those of the presenters and participants and “do not necessarily represent the policies or positions of the Department of Agriculture (USDA), the Environmental Protection Agency (EPA), or the United States Government (USG),” the report identifies various stressors that may contribute to bee colony collapse. Among them are (i) the parasitic mite Varroa destructor, described as “the single most detrimental pest of honey bees”; (ii) multiple virus species, potentially amplified by varroa; (iii) the bacterial disease European foulbrood; (iv) nutritional impacts; (v) honey bee gut microbes that “play key roles in enhancement of nutrition, detoxification of chemicals, and protection against diseases”; and (vi) “acute and sublethal effects of pesticides.”

The report indicates that the “most pressing pesticide research questions lie in determining the actual field-relevant pesticide exposure bees receive and the effects of pervasive exposure to multiple pesticides on bee health and productivity of whole honey bee colonies.” It also describes advances in genetic understanding of honey bees and how genetic variations may improve colony survival.