Survey: U.S. beekeepers lost 42 percent of honeybee colonies in past year

A survey has found that U.S. beekeepers lost 42 percent of their honeybee colonies in the past year.
A survey has found that U.S. beekeepers lost 42 percent of their honeybee colonies in the past year. | Contributed photo

Beekeepers in the U.S. lost 42 percent of their honeybee colonies over the year ending in April, a recent survey has found, coming amid a debate about how best to protect honeybees over the long term.

The survey was conducted by the Bee Informed Partnership, in collaboration with the Apiary Inspectors of America, with funding from the U.S. Department of Agriculture. More than 6,000 commercial and small-scale beekeepers from all 50 states responded to the survey, which asked them to track the health and survival rates of their honeybee colonies.

Winter loss rates for honeybee colonies improved slightly over last year, but summer losses were more severe. Winter loss rates dropped to 23.1 percent this year from 23.7 percent last year, but summer loss rates rose to 27.4 percent from 19.8 percent.

“We traditionally thought of winter losses as a more important indicator of health because surviving the cold winter months is a crucial test for any bee colony,” Dennis vanEngelsdorp, an assistant professor of entomology at the University of Maryland and project director of the Bee Informed Partnership, said.

“But we now know that summer loss rates are significant too,” vanEngelsdorp said. “This is especially so for commercial beekeepers, who are now losing more colonies in the summertime compared to the winter.”

Beekeepers who manage fewer than 50 colonies cited heavy infestations of varroa mites, which can easily spread between bee colonies. But vanEngelsdorp said many backyard beekeepers are not taking appropriate steps to control mites.

The colony losses cited by commercial beekeepers are not clear because those beekeepers tend to take aggressive action against mites.

“There is a question about whether or not pesticide exposure has something to do with those summertime losses” for commercial beekeepers, many of whom place their bees in agricultural areas, Randy Oliver, a commercial beekeeper who publishes beekeeping website, said. “It’s much harder to keep bees healthy in agricultural areas. It is not just a pesticide problem. It’s a transition of the land use in the agricultural areas. So beekeepers are struggling with that."

However, “if you look at the managed colony numbers in the United States, it has been ticking up the last few years, which tells you there are beekeepers who are doing pretty well. They would not be expanding their numbers of colonies unless they were profitable,” Oliver said.

Bayer CropScience called the report good news, given that for the second year in a row, winter losses of honey bee colonies were well below the historic average seen since these annual surveys began.

"The reasons for success are greater awareness of factors affecting honey bee health, particularly varroa mite, and better management, including the extensive use of the highly effective varroacide, Apivar," said Dick Rogers, principal scientist and entomologist at the Bayer Bee Care Center.

The survey comes against the backdrop of a large research effort to understand the health of honeybees. The Obama administration created a task force last year to build a federal strategy to promote bee health and combat the loss of pollinators. Its recommendations are expected in the coming weeks.

Some crops, such as almonds, depend entirely on pollinators, and honeybee colony losses create a financial burden for beekeepers. Furthermore, the total economic value of honeybee pollination services has been estimated at up to $15 billion annually.

“If beekeepers are going to meet the growing demand for pollination services, researchers need to find better answers to the host of stresses that lead to both winter and summer colony losses,” Jeffrey Pettis, a senior entomologist at the USDA and a co-coordinator of the survey, said.