EPA: Pesticides Linked to Bee Deaths Don’t Protect Soybean Crops
American farmers plant soybean seeds coated in pesticides linked to the mass die-off of honeybees on about a third of the 77 million acres that grow the crop in the United States. Now a new study from the U.S. Environmental Protection Agency has determined just how effective seeds treated with the pesticides, called neonicotinoids, are at controlling pests like the soybean aphid.
Not at all.
“U.S. soybean growers derive limited to no benefit from neonicotinoid seed treatments in most instances,” the authors of the study concluded after analyzing crop and pesticide data. “With regard to specific pest efficacy, there was almost universal agreement that neonicotinoid seed treatments are not typically effective against soybean aphids.”
Studies have implicated neonicotinoids, also called neonics, in the mass die-off of bees that pollinate a third of the global food supply. Those crops are worth $30 billion in the U.S. alone. Many scientists believe the pesticide is one of several interrelated factors—including disease, parasites, and poor nutrition—responsible for the apian catastrophe that has unfolded over the past decade.
“I think it’s the first step in reducing unnecessary use of these products,” Dennis vanEngelsdorp, an expert in honeybee health at the University of Maryland, said of the EPA study, released Thursday.
“It’s really good that we only use products when we need them,” added vanEngelsdorp, the author of studies that have found that pesticides, fungicides, and other agricultural chemicals lower bees’ resistance to disease.
Neonics are now the most used pesticides in the world, but before 2004 they were rarely sprayed on soybeans. That was the year the EPA approved neonics for soybean seeds. Annual insecticide use on soybeans subsequently soared from an average of 430,000 pounds a year to nearly 4 million pounds by 2008, according to the EPA study.
Farmers appear to be using the neonic-treated seeds indiscriminately. The researchers noted that 65 percent of growers do not target any particular soybean pest. And the scientists found that neonic-treated seeds are useless at controlling the most problematic bug, the aphid, because the insect does not appear in soybean fields during the three to four weeks when the pesticide is most effective.
EPA spokesperson Christie St. Clair said the research will help the agency determine whether to impose new restrictions on the use of neonics as part of an reassessment of the pesticides.
The study would appear to be good news for the bees. But vanEngelsdorp said it’s unclear what the consequences of banning neonic-treated seeds would be for honeybees. “We don’t have evidence that the seed treatment is having large impacts on honeybee health,” he said. “It could be affecting other pollinators, such as bumblebees.”
VanEngelsdrop said the bigger threat to bees is when neonics are sprayed on crops in a field and the wind blows the pesticide onto bee colonies.
“One of the problems is when you spray for aphids, those sprays can be toxic to bees,” he said. “You’ll see acute mortality and you’ll see dead bees in front of the colonies. Farmers have to be careful.”
If farmers now know that neonic-treated seeds are useless at controlling pests, will they spray more pesticides in the field? Not necessarily. The researchers found that most farmers already use neonic sprays.
Some environmental groups said the EPA study should prompt the agency to ban neonics.
“By confirming that they offer no benefit to U.S. soybean production, the Environmental Protection Agency has no course of action except to suspend all agricultural uses—including seed treatments—to protect pollinators and the planet,” Tiffany Finck-Haynes, a campaigner with Friends of the Earth, said in a statement.
St. Clair said the soybean seed study is the first of several the EPA will conduct on neonics and other crops as part of its review.
“We will be considering both risks and benefits for each of the neonicotinoids,” she said in an email. “Benefits assessments for corn and cotton will be part of the final analysis for registration review.”