It was a brutal winter once again for U.S. honey bee colonies, as for the fifth year in a row, about one-third of the colonies were lost.
According to the results released this week of the annual survey conducted by USDA and the Apiary Inspectors of America (AIA), total losses from managed honey bee colonies nationwide were 30% from all causes for the 2010-2011 winter. This is eerily similar to total losses reported in similar surveys done in the four previous years: 34% for the 2009-2010 winter, 29% for 2008-2009, 36% for 2007-2008, and 32% for 2006-2007.
“The lack of increase in losses is marginally encouraging in the sense that the problem does not appear to be getting worse for honey bees and beekeepers,” said Jeff Pettis, an entomologist with USDA’s Agricultural Research Service (ARS), who helped conduct the study. “But continued losses of this size put tremendous pressure on the economic sustainability of commercial beekeeping.” Pettis is the leader of the Bee Research Laboratory operated in Beltsville, MD, by ARS, the chief scientific research agency of USDA.
The survey, which covered the period from October 2010 to April 2011, was led by Pettis and by AIA past presidents Dennis vanEngelsdorp and Jerry Hayes. Beekeepers reported that, on average, they felt losses of 13% would be economically acceptable, but 61% of responding beekeepers reported having losses greater than the economically acceptable level. Average colony loss for an individual beekeeper’s operation was 38.4%. This compares to an average loss of 42.2% for individual beekeepers’ operations in 2009 and 2010.
Average loss by operation represents the percentage of loss in each operation added together and divided by the number of beekeeping operations that responded to the survey. This number is affected more by small beekeeping operations, which may only have 10 or fewer colonies, so a loss of just five colonies in a 10-colony operation would represent a 50% loss. Total losses were calculated as all colonies reported lost in the survey divided by the total number of bee colonies reported in the survey. This number is affected more by larger operations, which might have 10,000 or more colonies, so a loss of five colonies in a 10,000-colony operation would equal only a 0.05% loss.
Among surveyed beekeepers who lost any colonies, 31% reported losing at least some of their colonies without finding dead bee bodies — one of the symptoms that defines Colony Collapse Disorder (CCD). As this was an interview-based survey, it was not possible to differentiate between verifiable cases of CCD and colonies lost as the result of other causes that share the “absence of dead bees” as a symptom. The cause of CCD is still unknown.
The beekeepers who reported colony losses with no dead bee bodies present also reported higher average colony losses (61%), compared to beekeepers who lost colonies but did not report the absence of dead bees (34% in losses).
A total of 5,572 beekeepers, who manage more than 15% of the country’s estimated 2.68 million colonies, responded to the survey. A complete analysis of the survey data will be published later this year. The abstract can be found here. More information about CCD can be found here.
Source: Kim Kaplan, USDA-ARS News Service
For more information on USDA’s most recent “Honey Bee CCD Progress Report,” which was released in December, click here.
For information on an online database that was established last summer to track honey bee decline, click here.