Awareness of the decline of honey bees and other pollinators took a dramatic upturn after two recent events: the October 2006 release of the National Research Council report “Status of Pollinators in North America” (NRC 2007) followed by conspicuously high death rates of colonies of honey bees, Apis mellifera, in the winters of 2006-2007 and 2007-2008 (vanEngelsdorp et al. 2008), an event now known as Colony Collapse Disorder (CCD). All at once, managed pollinators were popularly recognized for what they always were: essential members of American agro-ecosystems.
Although the number of managed bee hives in the U.S. has been declining since the 1940s, the trend was exacerbated in the 1980s by the arrival of two exotic parasitic mites, Acarapis woodi and Varroa destructor (Webster and Delaplane 2001). But it is plain that more factors are implicated in bee decline than parasitic mites. A metagenomic analysis of bees from the 2006-2007 CCD event showed that virtually all bees from CCD-positive colonies had four pathogens: two viruses and two species of microsporidia, Nosema spp. (Cox-Foster et al. 2007). Risks from pesticides, both in-hive and out-, are also suspected; surveys at Penn State have found an average of six different pesticide residues in over 700 pollen samples analyzed from beekeepers across the country; pesticide frequency and levels are even higher in beeswax combs (Frazier et al. 2008).
Non-Apis bees, including all native bees and a few imports, are also in decline. Most non-Apis bees exist as non-managed wild populations; they represent a significant fraction of nature’s “free” background pollination (Delaplane and Mayer 2000). But there is disturbing evidence of regional extinctions. At least five species of North American bumble bees, Bombus spp., have disappeared from much of their native range since the late 1990s (Winter et al. 2006). Circumstantial evidence implicates spill-over infections of Nosema spp. and other pathogens from commercially-produced Bombus (Thorp and Shepherd 2005, Winter et al. 2006).
The problems with managed pollinators cannot be relegated to one or few causative agents. In the case of honey bees, it is likely that CCD is a product of negatively interacting factors in pathology, immunology, nutrition, toxicology, genetics, ecosystems management, and bee husbandry (CCD Steering Committee, 2007). In the case of non-Apis bees the list is the same – with the added disadvantage that the theory and practice of managing these bees are more poorly worked out.
A problem of this complexity and importance is best addressed by a nationally-coordinated team of experts with proven capacity in extension, genomics, pathology, toxicology, management, pollination, and behavior with Apis and non-Apis. The present CAP team originated from a rapid-response committee, NC508, Sustainable Solutions to Problems Affecting Honey Bee Health. Our group includes long-standing players in bee extension and research, Apis and non-Apis, including individuals involved in recent studies on CCD. Among the 21 collaborators, 18 have research appointments and 13 have extension appointments. Three have joined our team since the original proposal. Included here are the extension apiculturists of eleven states and the non-Apis extension specialists of two. The Integrated feature of this Coordinated Agricultural Project is inherent to the team.
Our long-term goal is to restore large and diverse populations of managed bee pollinators across the United States to sustain natural and agricultural plant communities.
The supporting goals of this proposal are to:
- Determine and mitigate causes of CCD: study the interactive effects of disease agents (pathogens, parasites) and environmental factors (pesticides, nutrition) on honey bee health
- Incorporate traits that help honey bees resist pathogens and parasitic mites and increase genetic diversity of commercially available stocks
- Improve conservation and management of non-Apis pollinators by identifying new or emerging pathogens and parasites, abiotic stresses, habitat degradation, and practices that optimize their pollinating efficacy
- Deliver research knowledge to client groups by developing a technology transfer program for queen breeders and a literature on Best Management and Conservation Practices for managed pollinators as an eXtension Community of Practice.