According to the annual survey conducted by USDA, the Bee Informed Partnership and the Apiary Inspectors of America – total losses of managed honey bee colonies from all causes were 21.9-percent for the 2011-12 winter. That’s a substantial drop compared to the previous five years. Total colony losses of 30-percent were found in the winter of 2010-11. Over the past five-years the biggest loss was 36-percent while the smallest had been 29-percent. The unusually warm winter may have contributed for the decline in colony losses. Survey co-leader Jeff Pettis – Research Leader of the USDA Ag Research Service Bee Research Laboratory – says a warm winter does mean less stress on bee colonies and may help them resist pathogens, parasites and other problems. But a direct scientific investigation of the weather connection has not been conducted.

Thirty-seven percent of beekeepers who reported losing colonies from any cause said they lost at least some of their colonies without finding dead bees. That is one of the defining symptoms of colony collapse disorder. UDSA says it was not possible to confirm whether these colonies had CCD or the losses were the result of other causes that share this symptom. Pettis says tracking CCD is complex since the cause is still unknown.

Nearly half of respondents reported losses greater than 13.6-percent. That’s the level of loss beekeepers have stated would be acceptable for their operations. According to USDA – continued losses above that level threaten the economic sustainability of commercial beekeeping.

More than 55-hundred beekeepers who manage nearly 15-percent of the country’s estimated 2.49-million colonies responded to the survey. A complete analysis of the data will be published later this year.