Winter’s loss of bees not as grim, study finds

Honeybees could be on their way back, according to a new federal report.

The collapse of bee populations across the country in recent years has led to warnings of a crisis in foods grown with the help of pollination. Over the past eight years, beekeepers have reported losses over the winter of nearly 30 percent of their bees, on average.

The new survey, published on Thursday, found that the loss of managed honeybee colonies from all causes has dropped to 23.2 percent nationwide over the winter that just ended, down from 30.5 percent the year before. Colony losses reached a peak of 36 percent in 2007 to 2008.

See

Page

The survey of thousands of beekeepers was conducted by the Department of Agriculture and the Bee Informed Partnership, an organization that studies apian health and management.

“It’s better than some of the years we’ve suffered,” said Dennis vanEngelsdorp, a director of the partnership and an entomologist at the University of Maryland. Still, he said, a 23 percent loss “is not a good number. ... We’ve gone from horrible to bad.”

He said there was no way to say at this point why the bees did better this year.

Jeff Pettis, the co-author of the survey who heads the federal government’s bee research laboratory in Beltsville, Md., warned. “One year does not make a trend.”

While much attention has been paid to colony collapse disorder, in which masses of bees disappear from hives, that phenomenon has not been encountered in the field in the past three years, vanEngelsdorp said. Instead, what has emerged is a complex set of pressures on managed and wild bee populations that includes disease, a parasite known as the varroa mite, pesticides, extreme weather and poor nutrition tied to a loss of forage plants.

Treating colonies for the varroa mite, an Asian parasite that first reached the United States in 1987, seems to have the most direct effect on stemming losses, vanEngelsdorp said.

“The beekeepers that are treating for varroa mites lose significantly fewer colonies than beekeepers that are not treating colonies for varroa mites,” and those who treat them four or five times a year do better than those who treat them only once or twice, he said.