In November of 2010, two U.S. Environmental Protection Agency scientists, an ecologist, Joseph DeCant, and a chemist, Michael Barrett, wrote an internal memo to the EPA’s insecticide risk management department expressing strong concerns about the potential dangers posed by a commonly available agricultural pesticide.
The subject of the memo was clothianidin, a synthetic, nicotine-based insecticide made by chemical and pharmaceutical giant Bayer, marketed to farmers to kill aphids and beetles, and widely used on corn crops in the U.S.
Upon reviewing several scientific studies on the pesticide, the EPA scientists had become convinced that, in addition to poisioning target pests that plague farmers, it is also “highly toxic” to honeybees. In the November memo they warned their colleagues of “the potential for long term toxic risk to honey bees and other beneficial insects.”
This is certainly not the first time the toxic effects of clothianidin on bees have come under scientific scruitiny.
Clothianidin has been banned in its maker Bayer’s home country of Germany since 2008, when the German Professional Beekeepers Association reported with alarm that 50-60% of honeybees in one region of the country died in a single season after visiting fields of corn and canola treated with the pesticide. Clothianidin has also been outlawed in Italy and France due to concerns about danger to bees.
In fact, in 2003, when Bayer first applied for a permit from the U.S. EPA to sell the chemical to farmers in America for use on food crops, the team of scientists who reviewed the inital application raised concerns about clothianidin’s toxicity to pollinating insects such as honeybees, and recommended further study.
But Bayer was granted conditional approval of clothianidin for sale that year by the EPA anyway.
In the years since, beekeepers across the country have noticed a dangerous decline in honeybee populations — an ecological crisis that threatens the American agricultural system. A mysterious illness, dubbed honeybee colony collapse disorder, which seems to cause worker bees to become disoriented and abandon their hives, has destroyed thousands of wild and commercial bee colonies.
Considering that honeybees are responsible for pollinating over a third of the food crops in the U.S., including popular foods like almonds, strawberries and watermelon, colony collapse disorder (CCD) threatens much more than bees and beekeepers — it threatens the very stability of the American food supply.
So far, there is no definitive scientific consensus that clothianidin, specifically, is behind CCD. Scientists have been exploring a wide variety of potential causes, including mites and viruses.
But entymologists, environmentalists and beekeepers agree that bees are generally under unprecedented stress from habitat loss, loss of natural food sources and overuse of synthetic pesticides. And that stress could well be making bee populations more vulnerable to CCD, whatever its cause.
Honeybees, beekeepers, and the farmers and consumers that depend on bees do not need one more toxic chemical threatening stressed bee populations. Scientific studies have repeatedly linked clothianidin to honeybee deaths. I urge U.S. residents to call on the EPA to withdraw clothianidin’s registation, and prevent further harm to the honeybees that help farmers grow America’s food.
Photo credit: USDA