PHOTO: A first-of-its-kind pilot study has found that some garden plants sold as "bee friendly" are actually poisonous to bees and other pollinators. Courtesy of PANNA.

ST. PAUL, Minn. - Home garden plants that are labeled as "bee friendly" in stores may actually harm and kill bees, according to a new first-of-its-kind pilot study.



The testing found that more than half the garden plants purchased at retailers, including some in Minnesota, had been pretreated with a pesticide harmful to bees and other pollinators, with no warning to gardeners.



Lex Horan, an organizer for the Pesticide Action Network, said that shows the need for quick action on multiple fronts.



"First of all, home garden centers have a responsibility to stop carrying plants that are pretreated with these neonicotinoid pesticides, and to take neonicotinoids off the shelves altogether," he said. "And then beyond that, EPA needs to do a swift, thorough review of neonicotinoids."



As of now, the Environmental Protection Agency isn't scheduled to review this pesticide until 2018.



A growing body of science has implicated neonicotinoids as one factor in colony collapse disorder, Horan said, with many U.S. beekeepers reporting losses of 40 percent to 90 percent of their bees last winter.



The way the EPA classifies neonicotinoids is a problem, said Dr. Vera Krischik, an entomologist at the University of Minnesota. The chemicals only are considered a "contact insecticide," she said, but plants do take them up through the soil.



"That accumulation increases through time, so after numbers of applications over years, the same plant gets more and more of this chemical in the pollen and nectar," she said. "When the bee or the butterfly or the beneficial insect feeds on it, it gets a very concentrated dose of this chemical."



Krischik also said the EPA didn't consider the impact of sub-lethal amounts of neonicotonoids, which are more difficult to track but can be just as deadly for bees.



"It affects a navigation system in their brain and they can't remember," she said. "They can't figure out how to get home, and so, at very low levels, they can't function. They just are out there and die."



Plants treated with these chemicals are thought to be widespread, but the plants used in this testing were purchased at Home Depot, Lowe's and other major retailers in the Twin Cities, the San Francisco Bay area and Washington, D.C. Seven of 13 were found to have levels of neonicotinoids poisonous to bees and other pollinators.



More information is online at action.foe.org and honeybeehaven.org.