COLUMBUS, Ohio (WOWO/Ohio News Service): Honeybee populations in the United States dropped by 44 percent last year, according to a new national survey of beekeepers.

Bees are essential to agriculture, responsible for more than $20 billion of the U.S. economy and contribute $217 billion globally, said Tiffany Finck-Haynes, a food-futures campaigner for the group Friends of the Earth. She isn’t convinced that varroa mites, cited in the report as one contributing factor, are to blame because, she said, beekeepers have been managing mites effectively for decades.

“What’s new and used pervasively, in agriculture and in our own backyards, is pesticides,” she said. “These pesticides are problematic because they’ll kill bees outright. They also weaken their immune system.”

Scientists with Bayer, a leading pesticide producer, have said bee losses can be mitigated if mites are managed better, and the company suggested that colonies simply can be replaced. However, Finck-Haynes argued that losing more than 40 percent of all bees every year is unsustainable. She pointed to a meta-analysis of more than 1,200 peer-reviewed studies connecting bee declines to exposure to neonicotinoid pesticides used heavily on plants that bees pollinate. Just two years after Italy banned neonicotinoids, Finck-Haynes said, bee populations nearly doubled. She said the controversial pesticide is prohibited in Europe but continues to be widely used in the United States.

“What we need from EPA is for them to adopt a federal unified plan and to place very strong restrictions on these pesticides and really pull them from the market,” she said, “because we know that’s the best way that they can protect the bees.”