(Beyond Pesticides, May 21, 2012) American farmers are growing increasingly more frustrated with the lack of commercially available seeds that have not been pretreated with pesticides. Farmers across the Midwest have called on federal officials this week to provide greater access to seeds without pesticide treatments. The request comes as scientists and beekeepers highlight the nearly pervasive use of neonicotinoids as seed treatments on corn as a critical factor in recent bee die-offs, including colony collapse disorder (CCD). Beekeepers from Minnesota to Ohio to Canada report large losses after their hives forage near treated cornfields. Scientists from Purdue University and a multi-year series of studies from Italy point to toxic dust, or neonicotinoid-contaminated powder from recently planted corn fields as key pesticide exposure pathways for bees. The request comes on the heels of a report aired by NBC Nightly News this week entitled â€śBee Deaths Linked to Pesticidesâ€ť, as well as recent reports of large bee kills in Ohio.
“Farmers want to be good stewards and neighbors by purchasing seeds and growing corn that supports healthy honey bees and successful beekeepers,” said Doug Voss, a Minnesota corn farmer who also keeps beehives. We have a genuine concern with the majority of corn produced having properties that can negatively impact honeybees.”
At least 94% of the nationâ€™s 92 million acres of corn will be treated with one of two neonicotinoids, both manufactured by Bayer. This area is greater than the total size of the state of Minnesota, Nebraska, or both Dakotas. In addition, these are among the largest honey producing states in the country, housing some of the nationâ€™s largest pollination services businesses. On average, USDA reports that beekeepers have been losing over 30% of their honey bee colonies each year since 2006.
â€śHoney bees are caught in the crossfire,â€ť said Steve Ellis, owner of Old Mill Honey Co. and the subject of the recent NBC Nightly News piece. â€śHoney bees, like mine, are subjected to increasingly toxic load of pesticides in corn fields. Itâ€™s time to rethink the use of neonicotinoids and provide farmers with better options that allow all of us to prosper.â€ť
Neonicotinoids, including clothianidin, imidacloprid, and thiamethoxam, are highly toxic to a range of insects, including honey bees and other pollinators. They are taken up by a plantâ€™s vascular system and expressed through pollen, nectar and gutation droplets from which bees forage and drink. They are particularly dangerous because, in addition to being acutely toxic in high doses, they also result in serious sublethal effects when insects are exposed to chronic low doses, as they are through pollen and water droplets laced with the chemical as well as dust that is released into the air when treated seeds that have been coated with the chemicals are planted. These effects cause significant problems for the health of individual honey bees as well as the overall health of honey bee colonies, including disruptions in mobility, navigation, feeding behavior, foraging activity, memory and learning, and overall hive activity.
Seeds treated with these insecticides are sticky and do not readily come out of common corn planting machines; so farmers often use talcum powder to help the seeds move more easily through the machine and into the ground. The talcum powder, mixed with the loose pesticide, creates a powerful pesticide dust that can directly coat and kill bees flying over freshly sown fields, and travel on wind to contaminate nearby untreated fields, creating even greater potential exposure for bees.
“We know that these insecticides are highly toxic to bees; we found them in each sample of dead and dying bees,” said Christian Krupke, PhD, associate professor of entomology at Purdue University and author of several recent bee studies. Dr. Krupke said, “Whatever was on the seed was being exhausted into the environment. This material is so concentrated that even small amounts landing on flowering plants around a field can kill foragers or be transported to the hive in contaminated pollen. This might be why we found these insecticides in pollen that the bees had collected and brought back to their hives.”
Despite their best intentions, even those involved in such efforts as the Institute for Agriculture and Trade Policyâ€™s (IATP) Working Landscapes Certificate program, farmers have struggled to find alternatives to neonicotinoid treated seeds. As conventional growers began to transition away from pesticide and herbicide treatments, they discovered that sourcing corn seed that was not treated with neonicotinoids was the most difficult challenge of all.
â€śCorn farmers engaged in Working Landscapes are concerned about pollinators, and are becoming increasingly aware of the impacts of neonicotinoids on bee populations, said Jim Kleinschmit, Rural Communities Program Director at IATP. â€śThe problem is that there isn’t much supply of bee-friendly seeds. The fact is, you just canâ€™t find high-yield, untreated corn seed anymore because of seed industry consolidation.â€ť
On March 21, 2012, commercial beekeepers and environmental organizations filed an emergency legal petition with the U.S. Environmental Protection Agency (EPA) to suspend use of clothianidin, urging the agency to adopt safeguards. The legal petition, supported by over one million citizen petition signatures, targets the pesticide for its harmful impacts on honey bees. The petition points to the fact that EPA failed to follow its own regulations. EPA granted a conditional, or temporary, registration to clothianidin in 2003 without a required field study establishing that the pesticide would have no â€śunreasonable adverse effectsâ€ť on pollinators. Granting conditional registration was contingent upon the subsequent submission of an acceptable field study, but this requirement has not been met. EPA continues to allow the use of clothianidin nine years after acknowledging that it had an insufficient legal basis for initially allowing its use. Additionally, the product labels on pesticides containing clothianidin are inadequate to prevent excessive damage to non-target organisms, which is a second violation of the requirements for using a pesticide and further warrants removing all such misbranded pesticides from use.
Learn more about the science, legal petition, and what you can do to help pollinators on Beyond Pesticidesâ€™ Protecting Pollinators program page.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.