Are Neonicotinoid Pesticides Killing the Honeybees?

Photo credit: Michelle Barte Photography

On May 27th, 2007, I first wrote about the mysterious illness that has been killing off honeybees in hives across North America known as 'colony collapse disorder,' or CCD. One of the bizarre aspects of CCD is that the worker bees just disappear and leave behind the queen, the honey, and the brood (or non-adult bees). It is assumed that they are going off to collect honey and either dying before they return or becoming disoriented and are unable to locate the hive again. One-third of the produce that Americans consume is pollinated by honeybees (including tomatoes, peppers, apples, cucumbers, broccoli, onions, squash, carrots, avocados, berries, melons, and almonds), so this is a serious threat to our food supply.

From the Milford, MA Daily News, May 10, 2008: A national survey of bee health from the Apiary Inspectors of America showed 36.1 percent of beehives were lost since last year. That's up from the previous year's losses of 32 percent. Some commercial beekeepers had far greater than 36 percent losses. "For two years in a row, we've sustained a substantial loss," Dennis vanEngelsdorp, president of the group, told the Associated Press. "That's an astonishing number. Imagine if one out of every three cows, or one out of every three chickens, were dying? That would raise a lot of alarm."

Back in 2007, when I wrote the first article about bees, many people theorized that the possible culprit was a pesticide called imidacloprid, manufactured by Bayer, AG, a German company. It is part of a class of insecticides called neonicotinoids, which are derived from nicotine. Now, scientists are even more concerned about another pesticide from the neonicotinoid class called clothianidin (also a Bayer product). Clothianidin is used on corn and canola and sold under the brand name Poncho. Many beekeepers and scientists suspect that it, in combination with other pesticides they are exposed to, weakens the immune system of bees, making them more susceptible to viruses and parasites such as the varroa mite.

The Popular Science website explains further: The U.S. Environmental Protection Agency regulates agricultural pesticide use, but this regulation does not account for the interaction of these chemicals that inevitably takes place through the bees' pollination processes. Some of these combinations of pesticides have been found to have a synergistic effect hundreds of times more toxic than any of the pesticides individually, says James L. Frazier, professor of entomology at Penn State. Bees' exposure to these toxic chemical combinations both outside of, and within, the home -- er, hive -- may cause behavioral changes. These changes include immune system blocks and disorientation, which may help to explain the CCD crisis of late.

The EPA fact sheet, which is posted online even admits that clothianidin is dangerous to bees: Clothianidin has the potential for toxic chronic exposure to honey bees, as well as other nontarget pollinators, through the translocation of clothianidin residues in nectar and pollen...
Clothianidin is highly toxic to honey bees on an acute contact basis (LD50 > 0.0439 μg/bee). It has the potential for toxic chronic exposure to honey bees, as well as other nontarget pollinators, through the translocation of clothianidin residues in nectar and pollen. In honey bees, the effects of this toxic chronic exposure may include lethal and/or sub-lethal effects in the larvae and reproductive effects in the queen.

That sounds pretty alarming, but there may be even more alarming research that is being withheld. The Raleigh News & Observer reports that a German investigation began on August 13th into whether Bayer submitted flawed studies on their product in order to get approval for its use. And recently, the National Resources Defense Council filed suit against the EPA because they failed to respond to a Freedom of Information Act request for the results of studies on clothianidin. In 2003, it was granted conditional approval by the EPA provided that they perform the studies. The EPA has never indicated whether the studies were done, and if they were, what the results were.

As explained by the San Francisco Chronicle, On July 17, after getting no response from the EPA about securing the studies, the environmental group filed a request under the Freedom of Information Act, which requires the records within 20 business days absent unusual circumstances. When the federal agency missed the August deadline, the group filed the lawsuit, asking the U.S. District Court in Washington, D.C., to force the EPA to turn over the records.

Scientists presenting at the American Chemical Society national meeting reported that dozens of pesticides had been found in samples of adult bees, broods, pollen and wax collected from honeybee colonies suspected to have died from symptoms of colony collapse disorder, including some neonicotinoids.

The Organic Consumers Association reports that in recent Congressional hearings, USDA was unable to account for the $20 million that Congress has allocated to the department for fighting CCD in the last two years. "This is a real mystery right now," said Dr. Gabriela Chavarria, director of NRDC's Science Center. "EPA needs to help shed some light so that researchers can get to work on this problem. This isn't just an issue for farmers -- this is an issue that concerns us all."


LINKS:
60 Minutes Segment on Colony Collapse Disorder
Video of bees that have adapted to have the ability to remove varroa mites from their bodies.
Video about applying even more pesticides to the bee hives to kill the mites.
Athens Herald, July 6th, 2008
San Francisco Chronicle, April 19th, 2008 (Quote: The hand of Congress works in equally mysterious ways: A new five-year farm bill under negotiation may spend a few million dollars saving bees, but definitely will spend billions on farm subsidy policies that contribute to their destruction.)
The Daily Green, August 1, 2008
The Guardian, September 29th, 2008
Vanishing Bees Movie