East and West Differences, plus Virus and Disease Differences…CCD is not as simple as we hoped
September 7, 2012
Editor’s Note: The journal article, “Pathogen Webs in Collapsing Honey Bee Colonies” is attached here. The study’s conclusions are consistent with CRE’s comments to the FIFRA Science Advsiory Panel which are available here.
From: Catch The Buzz
Kim Kaplan, Chief, Special Projects Information Staff
Agricultural Research Service U.S.D.A
Honey bees that succumb to Colony Collapse Disorder (CCD) carry a colony-specific group of three or four pathogens that tend to be unique to different geographic regions, according to a new study by Agricultural Research Service (ARS) scientists.
The paper, published this week in PLoSOne, is available online at: http://dx.plos.org/10.1371/journal.pone.0043562.
The most distinct difference in the makeup of the pathogen clusters was found between CCD-struck colonies in the eastern and western United States. In samples from eastern apiaries, the grouping tended to be all viruses. In the west, it was a mix of viruses and Nosema species, which are gut parasites. Specifically, Nosema apis and acute bee paralysis virus (ABPV) were linked with CCD colonies from western states, while these species were extremely rare in eastern honey bee colonies regardless of the presence of CCD.
Interestingly, collapsing colonies also differed overall from each other in the predominant pathogens, suggesting that these pathogens were lucky hitchhikers on the path to colony ruin, without any single factor being a consistent cause of collapse.
The largest single class of pathogens found in hives with CCD was RNA viruses, which are very small viruses associated with the mitochondria of host cells.
Each pathogen was present in some healthy colonies, but not at the levels found in CCD-struck colonies. The study confirmed an earlier finding, based on a small number of samples, that honey bee colonies showing CCD symptoms had significantly higher pathogen levels than colonies from apiaries that reported no CCD.
An association of RNA viruses and Nosema with CCD has been previously reported after studies of a small number of colonies, but this was the largest analysis of honey bee hives yet conducted.
The study describes genetic traits for several novel RNA viruses, and for other microbes associated with the hives that might have positive or negative effects on bee health.
More than 100 hives from nine states—California, Florida, Pennsylvania, Maryland, Nebraska, New York, South Dakota, Wisconsin and Washington—were sampled between 2004 and 2008 and then analyzed for this study.
The geographic differences also indicate that it is unlikely that any single recognized agent is responsible for CCD, making the search for unifying predictors more complicated, according to ARS entomologist Jay Evans at the agency’s Bee Research Laboratory in Beltsville, Md. Evans co-led the study with ARS research associate Scott Cornman, and with help from colleagues Jeff Pettis and Judy Chen at the Beltsville lab. Researchers from the University of Maryland and North Carolina State University were also part of the team, which received support from ARS and the National Honey Board.
ARS is the U.S. Department of Agriculture’s chief intramural scientific research agency.
Leave a Comment