USDA and EPA Report: Honey Bee Decline Caused By Multiple Factors

Earlier this month, the EPA and USDA, along with beekeepers and academic researchers, released a report attributing the recent sharp decline in U.S. honey bee colonies to multiple factors, including pesticides, parasites, viruses and malnutrition. The report, summarizing the proceedings of the National Honey Bee Health Stakeholder Conference held in October 2012, stated that commercial honey bee colonies lost 31 percent of their population last winter, more than double the historical rate of loss (about 10 to 15 percent), and in line with rates documented since the start of Colony Collapse Disorder (CCD) in 2006. Because many agricultural crops depend on pollination by bees, CCD threatens crop yields and thus, food prices and food security. The report synthesizes the current state of knowledge of CCD and factors affecting honey bee health for the purpose of better developing research priorities and best management practices for beekeepers and the agricultural community.

The report identified pesticide effects on honey bees as “a primary concern,” and called for further research on the risks to honey bee decline associated with pesticide exposure. Based on current research, it is “not clear” whether pesticide exposure is a major factor in the deterioration of honey bee health, or if it specifically affects honey production or pollination. On the other hand, the report states that it is clear “that in some instances honey bee colonies can be severely harmed by exposure to high doses of insecticides” used on crops. Studies have also shown that sublethal doses of pesticides can increase susceptibility to a gut pathogen.

Overall, the report emphasizes that there is no “single silver bullet” to alleviating CCD and instead recommended a mix of strategies including habit enhancement, better-targeted pesticide use, and breeding bees for disease- and pest-resistance.

The report was released just days after the European Union voted to partially ban neonicotinoids, following a European Food Safety Authority finding that the pesticides posed an “acute risk” to honey bees. EPA stated that it has accelerated the registration review process for neonicotinoid insecticides, citing concerns over the pesticides’ potential effects on bees, and would require the completion of new field studies on oral toxicity, contact exposure, and toxicity to larvae.

EPA’s Acting Administrator Bob Perciasepe said the agency’s guidance document for improving “bee kill” investigations will be released this month. The preparers of the report, the National Honey Bee Health Stakeholder Conference Steering Committee, will next prepare an Action Plan in late 2013 or early 2014.