Preliminary Results: Honey Bee Colony Losses in the United States, Winter 2012-2013

EMBARGOED UNTIL MAY 7th.

May 1, 2013

Dennis vanEngelsdorp1*, Nathalie Steinhauer1, Karen Rennich1, Jeffery Pettis2, Eugene J. Lengerich3, David Tarpy4, Keith S. Delaplane5, Angela M. Spleen3, James T. Wilkes6,

Robyn Rose7, Kathleen Lee8, Michael Wilson9 , John Skinner9 , and Dewey M. Caron 10

for the Bee Informed Partnership.

Note: This is a preliminary analysis. A more detailed final report is being

prepared for publication at a later date.

The Bee Informed Partnership (http://beeinformed.org), in collaboration with the Apiary

Inspectors of America (AIA) and the United States Department of Agriculture (USDA),

is releasing preliminary results for the seventh annual national survey of honey bee

colony losses. For the 2012/2013 winter season, a total of 6,287 U.S. beekeepers

provided validated responses. Collectively, responding beekeepers managed 599,610

colonies in October 2012, representing about 22.9%1 of the country’s estimated 2.62

million colonies.

Preliminary survey results indicate that 31.1% of managed honey bee colonies in the

United States were lost during the 2012/2013 winter. This represents an increase in loss

of 9.2 points or 42% over the previous 2011/2012 winter’s total losses that were

estimated at 21.9% (Figure 1). This level of loss is on par with the 6 year average total

loss of 30.5%2.

On average, U.S. beekeepers lost 45.1% of the colonies in their operation during the

winter of 2012/2013. This is a 19.8 point or 78.2% increase in the average operational

loss compared to the previous winter (2011/2012), which was estimated at 25.3%. The

difference between average loss and total loss is explained by the respondent pool: while

a majority of the respondents (95%) were backyard beekeepers, they managed a small

fraction of the colonies represented in the survey (6%). For this reason total loss (which

is more heavily influenced by commercial beekeeper losses) is more representative of

national losses.

Survey participants indicated that they considered a loss rate of 15% as “acceptable,” but

70% of them suffered losses greater than this.

1 Based on NASS 2012 figures

2 Previous survey results found a total colony loss in the winters of 21.9% in the winter of 2011/2012, 30% in 2010/2011, 34% in 2009/2010, 29% in 2008/2009, 36% in 2007/2008, and 32% in 2006/2007 (see figure attached)

The Bee Informed Partnership is funded by the National Institute of Food and

Agriculture, USDA.

1. University of Maryland; dennis.vanengelsdorp@gmail.com 717-884-2147;

2. USDA-ARS Bee Research Laboratory

3. The Pennsylvania State University,

4. North Carolina State University

5. University of Georgia

6. Appalachian State University

7. Robyn Rose, USDA Animal and Plant Health Inspection Service,

8. University of Minnesota

9. University of Tennessee

10. Oregon state University

*Corresponding author