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Decline of bee colonies: The sting of pesticides

This week, the European Commission began a two-year moratorium on the nerve-agent pesticides known as neonicotinoids, which are suspected in a global decline in bee colonies — a phenomenon that, in turn, dealt a serious blow to fruits and vegetables that depend on bee pollination. The commission banned clothianidin, imidacloprid, and thiametoxam, which are meant to kill unwanted insects but also get absorbed by bees through pollen, nectar, dust, and sap.

Those pesticides are also widely used in the United States, where bee pollination is annually responsible for $15 billion of the nation’s fruits, vegetables, and nuts. The number of domestic bee colonies has crashed from 6 million in 1947 to 2.5 million today. That may still sound like a lot of bees, but it’s not. California almond growers alone need at least 1.5 million colonies for pollination, Washington state apple growers need 250,000, and even Maine’s wild blueberry crop this year reportedly required up to 70,000 colonies, or about 3 billion bees, to convert blooms to berries. In a federal report this year, researchers said at the current rate of loss, there is no cushion left for bees “to meet the pollination demands of US agricultural crops.”


Other factors, such as mites, fungus, and viruses, may be at play in the collapse, but researchers have repeatedly identified neonicotinoids as a key culprit. Last month, the Oregon agriculture department restricted two neonicotinoid pesticides after 50,000 bees were found dead or dying this summer in a Target parking lot. The bees were pollinating a tree sprayed with pesticides. US Representative Earl Blumenauer, an Oregon Democrat, has filed federal legislation to suspend use of neonicotinoids pending further review. But the federal government has been slow to take decisive action. The Environmental Protection Agency says its scientific conclusions thus far “are similar to those expressed” by the Europeans and this year ordered new labeling on neonicotinoid products, saying the product can kill bees if applied in their presence.

But critics say the pesticide, whether sprayed or applied as a seed treatment, is absorbed into plants and remains toxic to bees all season long. There may be no single solution to the loss of bees, but these pesticides are sufficiently implicated that the EPA should match the European moratorium. The bees have already been stung enough.