The Neonic Lowdown

What EPA's Latest Neonic Documents Mean for Farmers

Emily Unglesbee
By  Emily Unglesbee , DTN Staff Reporter
Connect with Emily:
Neonicotinoid seed treatments are under scrutiny from the EPA, and farmers have an opportunity to comment on some of the agency's conclusions. (DTN photo by Pamela Smith)

ROCKVILLE, Md. (DTN) -- EPA doled out hundreds of pages on the risks and benefits of neonicotinoid insecticides on Dec. 15 -- an early Christmas "gift" of sorts for farmers.

Tempting as it to ignore these data-heavy documents, most corn, soybean and cottonseed in the country is coated with these chemicals, so the majority of row-crop farmers have a serious stake in the agency's registration review of them. EPA wants to hear from these farmers; many of these review documents are open to public comment.

To refresh, neonicotinoids are insecticides most commonly used in seed treatments to control a variety of soil and foliar insect pests in field crops such as corn, cotton, sorghum, sugar beets and soybeans. These are the neonicotinoids under EPA review: clothianidin (Poncho, from Bayer), thiamethoxam (Cruiser, from Syngenta) and imidacloprid (Gaucho, from Bayer and Valent USA).

So let's dig in, starting with the most significant and pressing items for growers:


Last year, EPA released pollinator-only risk assessments for the neonicotinoid insecticides. They concluded that the foliar use of these chemicals in the pre-bloom and bloom periods of cotton could pose a risk to honey bees. (See DTN's story here:….)

Now the agency is releasing the other side of the equation -- an assessment of the benefits cotton growers see from foliar applications of neonicotinoids and how losing access to them might affect their operations.

EPA is breaking its own protocol by asking for grower input now (just as they did with the risk assessments), before they make a final decision on whether to restrict neonicotinoid use in cotton.

In this assessment, EPA considers how spraying restrictions at different times of the growing season would affect growers. For example, they conclude that a restriction on spraying the chemicals from pinhead square through harvest would affect 1.2 million acres of cotton and, on average, cost producers an extra $5.70 per acre, for a total industry loss of $6.9 million a year. A restriction from the beginning of bloom through harvest, on the other hand, would only affect 500,000 acres of cotton and cost producers $1.7 million a year. You can read the full document here:….

Farmers can comment on this document and are encouraged to do so by the agency. Using this EPA press release, select the link for the chemical you wish to comment on here, which will take you to the official EPA docket:…. The public comment period closes April 21, 2018.

For a guide on how to comment effectively on an EPA document, see this DTN story:….


Just over three years ago, EPA released a document titled "2014 Benefits of Neonicotinoid Seed Treatment to Soybean Production," which concluded that farmers saw no significant economic benefit from neonicotinoid seed treatments on soybeans. It set off a firestorm in the industry. Many academic entomologists from Midwestern and some Southeastern states announced that they largely agreed with this conclusion, with a few exceptions for serious soil pest problems. The registrants of the neonicotinoids in question -- Bayer, Syngenta, and Valent USA -- disagreed strongly and released their own analysis of soybean seed treatment benefits.

Fast forward to 2017. After poring over 40,000 public comments on this controversial document, EPA responded to them and released a revised conclusion. See it here:….

The agency acknowledged two key situations where soybean neonicotinoid seed treatments are likely to benefit farmers: in the Midsouth, where pest pressure is high, and in Midwestern fields where the bean leaf beetle is an established pest.

But beyond those scenarios, EPA has mostly stuck to its guns, concluding: "...the benefits of neonicotinoid seed treatments are generally low for most soybean growers in the United States."

The registrants continue to disagree with this, but the document is not open for comment anymore. EPA has said its piece, and now farmers must wait until the agency finalizes its registration review of neonicotinoids sometime in 2018 to see what effect this revised conclusion will have on soybean seed treatments.


As part of its ongoing registration review, EPA also released its analysis of the potential risks posed to aquatic species, mammals, birds and plants from thiamethoxam (Cruiser, from Syngenta, mostly used on corn and cottonseed) and clothianidin (Poncho, from Bayer, mostly used on corn and soybean seed).

These risk assessments are highly technical analyses of toxicology and usage data on these insecticides. The registrants of the two products, Bayer and Syngenta, are busy reviewing them and preparing similarly technical responses for the public comment period, which closes April 21.

Farmers should also comment if they feel their experience with the chemicals will be relevant to these risk assessments:…. For help on making your comment matter to the EPA, see this DTN story:….

Emily Unglesbee can be reached at

Follow her on Twitter @Emily_Unglesbee


Emily Unglesbee