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The butterfly effect
John Pleasants looks at Bt corn, Bt cotton, Roundup Ready soybeans and the monarch butterfly from Hawaii to Iowa.
- John Pleasants' research has taken him to Hawaii and East Africa. But a good portion of his research activities take place in the middle of Iowa and in the middle of one of the biggest environmental issues genetic modified organisms (GMOs) has faced.
The Bt gene was inserted into the corn genome to stop European corn borers from destroying Iowa's most valuable row crop. But the Bt gene can affect species related to European corn borers such as butterflies and moths, adversely affecting their digestive system.
It is the monarch butterfly and the debate on whether Bt corn was killing off the population of this beautiful butterfly that brought Pleasants into this research area.
Pleasants, an adjunct assistant professor in the Department of Ecology, Evolution and Organismal Biology, says the monarch butterfly feeds exclusively on the leaves of milkweed plants that are prevalent throughout the state. Milkweed plants outside of cornfields receive very little corn pollen and thus are not a problem. And while there are milkweed plants in cornfields, Pleasants' research indicates there isn't enough of an issue to cause a problem with the monarch butterfly population.
"Very rarely do milkweed plants inside of a cornfield get enough Bt corn pollen on their leaves to cause a problem," he said. "Our objective was to put together the data that we had collected in a series of scientific papers that showed that Bt corn pollen posed very little risk to monarch butterflies."
Just as Pleasants and his collaborators on the project were all set to go to Washington, D.C. to testify about the issue, terrorists flew two airplanes into the World Trade Center.
"Our report got ‘lost' because of 9-11," he said. "It never got the kind of public attention that we thought it would and in the minds of many in the public, our
research never surfaced."
Pleasants' investigation has raised other questions as his research has morphed from studying Bt corn to GMO (Roundup Ready) soybeans. The same genetic techniques used to make Bt corn were used to insert a gene into soybeans to make them resistant to Roundup herbicide. Farmers using this type of soybean and Roundup herbicide effectively kill all weeds, including milkweeds.
"The one thing that seems clear is the effect that Roundup Ready soybeans has on getting rid of weeds," he said. "Almost all patches of milkweed are gone in the areas I've monitored. Is this bad for the monarch butterfly? There are still a lot of milkweed plants in the non-farm-field areas but a vast majority of monarchs feed on milkweed in agricultural fields."
Funding for Pleasants' research has been provided by the Environmental Protection Agency, the same agency that has funded his research on the possibility of gene flow between GMO cotton and native Hawaiian cotton.
Working with EEOB colleague Jonathan Wendel, Pleasants says the gene flow concern with Bt cotton isn't nearly as great in the continental U.S. because there are few places (Florida and Arizona) where native cotton species are found.
Pleasants and Wendel went to many of the Hawaiian Islands, including one "that no one ever goes to," and found that the native species was visited by several different kinds of bees not native to the islands such as carpenter bees and honeybees. These bee species range widely as they forage so GMO cotton fields would have to be situated several miles away from native cotton populations to prevent gene flow.
He is also working in Kenya, Uganda and Tanzania on a USAID-funded risk assessment project with Bt cotton.
John Pleasants
Around LAS
October 1-14, 2007
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