Bayer: Bee-Toxic Pesticide Killed German Bees, But Is Safe in America

Bayer’s response to all the negative press surrounding the bee-toxic pesticide clothianidin: go into spin mode.

Bayer: Bee-Toxic Pesticide Killed German Bees, But Is Safe in America


As we have detailed in a number of stories, a pesticide (clothianidin) produced by Bayer may be  responsible, at least in part, for the precipitous decline of the bee population in the last few years. The pesticide was approved on the basis of a study that the EPA knew to be faulty. There is little evidence supporting Bayer’s claim that clothianidin is safe (and a growing stack of evidence that it isn’t).

Bayer’s response to all the negative press surrounding clothianidin: go into spin mode. But the company’s recent blog post on clothianidin’s safety is itself full of holes.

Take this sentence, for example: “Bayer CropScience was recently made aware of an unauthorized release
from within the Environmental Protection Association (EPA) of a document
regarding the seed treatment product, clothianidin, which is sold in
the United States corn market.” The document’s release was not “unauthorized”; it was available through the Freedom of Information Act. It was forwarded to Colorado beekeeper Tom Theobald by an EPA employee, who first made Theobald aware of it. But that’s almost beside the point.

Bayer also notes that its flawed study “was peer-reviewed and published in the Journal of Economic Entomology, and that the EPA initially called it “scientifically sound” and said it “satisfies the guideline
requirements for a field toxicity test with honey bees.”

Indeed, that was what the Agency said at first blush. But the recently unearthed document reveals the EPA’s concern with the study. “Another field study is
needed to evaluate the effects of clothianidin on bees through
contaminated pollen and nectar,” it says. In other words, the study doesn’t satisfy guideline requirements for a core study on honey bee safety.

Bayer’s response? “This was an incomplete document, something that they were working on,” says Jack Boyne, Director of Communications at Bayer CropScience. “The study in question was a peer-reviewed, scientifically valid study.”


Then there’s this statement in the release: “Clothianidin is the leading seed treatment on corn in the United States
and has been used extensively for over six years without incident to
honey bees.” That’s disingenuous at best. Bayer has already admitted that the misapplication of clothianidin was responsible for killing two-thirds of beekeepers’ bees in the Baden-Württemberg region of Germany.

A Bayer press release from 2008 explains that “The bee die-offs which occurred in spring
2008 in Southwest Germany as the result of faulty application of the
active ingredient clothianidin set off a controversial discussion on the
use of pesticides for seed treatments.” Bayer won’t accept fault for the incident. Nevertheless, its own 2008 press release goes against its 2010 statement that clothianidin has been used without incident to honey bees. (Bayer responds that the statement was only meant to refer to clothianidin use in the U.S.)

A number of factors contributed to the disaster in Germany–a combination of strong winds, dryness in the area, and faulty seed coatings from a local seed treatment company are all responsible. “I don’t think it will happen again. This is one of the leading products in
corn as a seed treatment, and we have not seen this type of incident since,” says Boyne.

But even if clothianidin is entirely safe if applied correctly–and we don’t believe it is–Bayer can’t guarantee that the pesticide will be used properly by growers. Should the fate of our bees–and a third of American agriculture–really rest in the hands of seed treatment companies and changeable weather conditions?



About the author

Ariel Schwartz is a Senior Editor at Co.Exist. She has contributed to SF Weekly, Popular Science, Inhabitat, Greenbiz, NBC Bay Area, GOOD Magazine and more