The following is a summary of a preliminary report on winter mortality of honey bee colonies in the US over the past winter. The full report can be read on the eXtension website.
"The Apiary Inspectors of America (AIA) and the United States Department of Agriculture (USDA) conducted an online survey to estimate honey bee colony losses for the 2010/2011 winter season. A total of 5,572 U.S. beekeepers, or 20% of the estimated number of beekeepers in the country, responded. Collectively these beekeepers managed over 15% of the country’s estimated 2.68 million colonies.
Preliminary survey results indicate that 30% of managed honey bee colonies in the United States were lost during the 2010/2011 winter. The percentage of losses have remained relatively steady (near or above 30%) over the last 5 years. Specifically, previous survey results indicated that 34% of the total colony loss in the winters of 2009/2010; 29% in 2008/2009; 36% in 2007/2008; and 32% in 2006/2007."
According to Andrew Joseph, State Apiarist with the Iowa Department of Agriculture and Land Stewardship, "Compared to the national average, Iowa beekeepers have experienced a higher percentage of losses, with preliminary estimates of winter losses from this past winter at 50 – 55%. While this is better than the previous winter, it is still unsustainable for the beekeeping industry."
The national survey agrees. The 2010/2011 survey reported a 9.0% decrease in the average operational loss experienced by U.S. beekeepers compared to the winter of 2009/2010. Speaking to sustainability, beekeepers in the AIA /USDA survey reported that, on average, they felt losses of 13% would be acceptable. Sixty-one percent of responding beekeepers reported having losses greater than this. Replacing 30% of the nation’s colonies annually is not considered sustainable over the long-term.
It is important to note that this survey only reports on losses that occur during the winter and does not capture the colony losses that occur throughout the summer. Preliminary data from other survey efforts suggest that these “summer losses” can also be significant.
Report authors are: Dennis vanEngelsdorp, Pennsylvania State University & Apiary Inspectors of America (AIA); Jerry Hayes, Florida Department of Agriculture & AIA; Dewey Caron, Oregon State University; James T. Wilkes, Appalachian State University; Robyn Rose, USDA APHIS Plant Protection and Quarantine; and Jeff Pettis USDA-ARS Bee Research Laboratory.