Letter to Producers of Bt Corn Seed

Posted: 13-Jul-1999; Updated: 27-Jun-2003

I am writing you to seek your cooperation in an effort to avert potential unintended harm to monarch butterflies, and other butterflies and moths, from Bt corn. Specifically, beginning with the year 2000 growing season, I am requesting that [Monsanto's/Novartis BioTechnologies'/ Dow AgroSciences'/AgrEvo's] contracts with farmers planting Bt corn include a provision requiring farmers to plant a buffer of non-Bt corn around fields of Bt corn, with the buffer being at least 40 feet wide. Because most corn pollen lands close to corn plants, this measure will greatly reduce the flow of pollen from Bt corn into habitats of butterflies and moths not targeted by Bt pesticides.

As described more fully in a petition the Environmental Defense Fund is filing today with the U.S. Environmental Protection Agency, a newly published study indicates that Bt corn pollen can kill monarch butterfly caterpillars. In that laboratory study, monarch caterpillars died after eating milkweed dusted with pollen from Bt corn. Other butterflies and moths, including rare and endangered species, may also be killed by pollen from Bt corn. The primary pest targeted by Bt corn -- the European corn borer -- is itself a moth, and Bt toxins are known to be toxic to a variety of butterfly and moth species.

Areas adjacent to cornfields often contain milkweed plants ? the exclusive food for monarchs ? as well as other plants that may be food for other species of butterflies and moths. While monarchs and other butterflies and moths face other significant threats, such as habitat loss, contamination of their food supply by Bt pollen can only exacerbate these problems. Researchers are now investigating in the field the extent to which pollen from Bt corn threatens populations of butterflies and moths.

Prudent steps can be taken to reduce the likelihood of potentially serious effects on monarchs and other butterflies and moths while such additional research is being conducted. EDF is asking that all of your contracts with Bt corn growers require that, beginning in the 2000 growing season, non-Bt corn be planted for 40 to 80 feet on all sides of each field planted with Bt corn. While planting such a buffer would be practicable for most farmers, the attached petition provides exemptions where buffers are not feasible.

We would like to appropriately recognize companies that are willing to proceed with caution, so as to avoid potential harm to important wildlife. Please contact me by August 16 to indicate whether you intend to take the requested action in the year 2000 growing season.

The enclosed Petition to Administrator Carol Browner of the Environmental Protection Agency simultaneously requests that the Agency mandate similar measures. However, we hope and prefer that your company initiates voluntary measures to prevent unanticipated problems associated with the use of your product.

Very truly yours,

Fred Krupp
Executive Director

Read the petition
Read the news release