NEW YORK — A prolonged and mysterious reduction in the population of the nation’s honeybees, a trend worrisome both to beekeepers and farmers who depend on the insects to pollinate their crops, apparently worsened last year.
In an annual survey released Wednesday by the Bee Informed Partnership, a consortium of universities and research laboratories, about 5,000 beekeepers reported losing 42.1 percent of their colonies in the 12-month period that ended in April. That is well above the 34.2 percent loss reported for the same period in 2013 and 2014, and it is the second-highest loss recorded since year-round surveys began in 2010.
Most striking, however, was that honeybee deaths spiked last summer, exceeding winter deaths for the first time. Commercial beekeepers, some of whom rent their hives to farmers during pollination seasons, were hit especially hard.
“We expect the colonies to die during the winter, because that’s a stressful season,” said Dennis vanEngelsdorp, an assistant entomology professor at the University of Maryland who directs the survey for the bee partnership. “What’s totally shocking to me is that the losses in summer, which should be paradise for bees, exceeded the winter losses.”
Bees are not in danger of extinction, but their health is of major concern to agriculture.
Nobody knows with certainty why the deaths are occurring.