Science Paper Issues Biotech Caution
Willie Vogt
Farm Progress
July 3, 2001

John Obrycki is used to the media calling him to talk about corn and butterflies. The Iowa State entomologist is known for his work with potted milkweeds and a second lab feeding study that got quite a bit of attention last season. Looks like he might get a few more calls this year.

Obrycki, along with John Losey, the Cornell University entomologist who's lab work got the world's attention when he showed pollen from Bt corn could be toxic to Monarch caterpillars, and two other collaborators, have written a new paper on the topic of Bt corn. Their paper is a cautionary tale about biotech use for the sake of insurance when there may be unknown consequences.

...The article looks at planting rates of Bt corn, use rates of insecticides and yield studies of resultant crops from Corn Belt states. They settle on some conclusions:

Bt corn is not reducing insecticide use for corn borer. Obrycki tells Rooster.com that before Bt corn came on the scene about 2 to 3% of acres hit by European Corn Borer were treated with insecticides. Insecticide use hasn't fallen but Bt corn use now covers about 18% of U.S. corn acres (according to USDA's latest figures). Bt corn is a kind of insurance policy used in case borers appear. Obrycki says that using Bt corn as insurance is no different from spraying an insecticide just in case you might have a problem. "If you only have corn borer pressure once every seven years if you use Bt corn every year does it pay for the one bad year?" he asks. But these entomologists say that based on the features on which biotech is sold -- lower pesticide use and economic benefit -- the case for Bt corn isn't too strong. "This is a very powerful technology and may be useful for other insects, but does it really have a good role to play in the midwestern U.S.?" asks Obrycki. "From our point of view, based on the past two or three years of data, the answer would be no."

The entomologists say that what's needed is more comprehensive testing. "If we had tested for non-target insects before Bt corn was labeled and knew the real mortality issues in the field, as we're finding now, it might have been different," he says. They say, "potential risks are not thoroughly addressed in the U.S. governmental registration process, an oversight that should be attended to."