Despite multiple incidents in Ontario, Minnesota, Illinois, New York and Indiana, where the death of bees at planting time has been linked to corn seed treatments, a spokesperson for Bayer Crop Science said there is little reason to point the finger at insecticides.
“We think that there is very poor correlation between the treatment of corn with clothianidin and the bee kills,” said Alan Ayers, the company’s head of product stewardship in the United States.
Ayers pointed to a recent U.S. Environmental Protection Agency decision regarding clothianidin, a Bayer neonicotinoid insecticide and seed treatment better known as Poncho.
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Earlier this year, beekeepers and environmental groups in the U.S. submitted a petition with more than a million signatures, asking the EPA to suspend the use of clothianidin because it poses an “imminent hazard” to bees.
The EPA denied the request in July, noting there isn’t sufficient evidence proving clothianidin is significantly reducing bee populations in America.
However, EPA scientists are reviewing neonicotinoids this year to determine if restrictions are needed to protect pollinators and the environment.
Purdue University entomologist Christian Krupke, who has raised questions about the threat of neonicotinoids to bees, also said that nearly all of the corn acres in North America are grown with treated seed, even though there is little evidence of efficacy.
When asked if there are peer-reviewed studies confirming that seed treatments boost yield, Ayers offered data but did not refer to a particular study.
“If you look at one of our leading seed treatment products, clothianidin, when you look across a lot of data, we can see an increase in corn yields of about six to 14 bushels per acre,” he said.
“I think some of those (figures) are based on side by side treatments. But to say all of them, we would have to check.”
Regarding the argument that insecticides should be used only when pests reach an economic level, Ayers said it’s tough to scout for soil borne pests.
He also said the debate has raged for decades over preventive treatments versus on-demand applications, but producers have clearly chosen prevention.
“It (seed treatment) has really succeeded because it’s the most efficient, effective and productive way,” he said.
“It just depends on who you talk to in the scientific world. These (seed treatments) are probably one of the most effective and efficient ways of meeting IPM (Integrated Pest Management) goals.”