Honey bee colony losses nationwide were approximately 29 percent from all causes from September 2008 to April 2009, according to a survey conducted by the Apiary Inspectors of America (AIA) and the U.S. Department of Agriculture.

This is less than the overall losses of about 36 percent from 2007 to 2008, and about 32 percent from 2006 to 2007, that have been reported in similar surveys.

"While the drop in losses is encouraging, losses of this magnitude are economically unsustainable for commercial beekeeping," said Jeff Pettis, research leader of the Agricultural Research Service (ARS) Bee Research Laboratory in Beltsville, Md. ARS is USDA's principal intramural scientific research agency. The survey was conducted by Pettis; Dennis vanEngelsdorp, president of AIA; and Jerry Hayes, AIA past president.

About 26 percent of apiaries surveyed reported that some of their colonies died of colony collapse disorder (CCD), down from 36 percent of apiaries in 2007-2008. CCD is characterized by the sudden, complete absence of honey bees in a colony. The cause of CCD is still unknown.

As this was an interview-based survey, it is 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.

However, among beekeepers that reported any colonies collapsing without the presence of dead bees, each lost an average of 32 percent of their colonies in 2008-2009, while apiaries that did not lose any bees with symptoms of CCD each lost an average of 26 percent of their colonies.

To strengthen the beekeeping industry, ARS recently began a five-year, area-wide research program to improve honey bee health, survivorship and pollination. Honey bee pollination is critical to agriculture, adding more than $15 billion to the value of American crops each year.

The survey checked on about 20 percent of the country's 2.3 million colonies.

A complete analysis of the survey data will be published later this year. An abstract of the data is available on line at: http://maarec.cas.psu.edu/pdfs/PrelimLosses2009.pdf.