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.
First, let's get one issue straight. Obrycki and Losey are in the second year of a field study of survival of Monarch caterpillars with very promising first-year data. "John and I are doing a study of larval survival in a number of habitats," says Obrycki. "We could not find any significant difference in survival of caterpillars in Bt corn or in non-Bt corn. But that's just one year of data. We'll see how it turns out this year."
These entomologists aren't out to trash biotechnology. Instead, their orientation has been towards research of unintended consequences. The early Monarch warning that Losey issued in 1999 has been attacked by industry. "A lot of people say they have data that counters the data John and I have found in our research, but the information has never been published," Obrycki observes. Obrycki's potted milkweed study got as much attention by the biotech industry as Losey's.
The new paper -- "Transgenic Insecticidal Corn: Beyond Insecticidal Toxicity to Ecological Complexity" -- was published in the May 2001 journal, BioScience. In the article, the entomologists along with Orley Taylor, professor of entomology and ecology and evolutionary biology, University of Kansas, Lawrence, and Laura Jesse, a graduate student at Iowa State University, reviewed recent scientific studies that detail Bt corn's effects on insects and other microorganisms.
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."
Currently the U.S. Environmental Protection Agency (EPA) is in the process of reviewing all Bt crops. These crops are up for renewal at the end of September 2001. How does this latest article play into that debate: "I think it just provides more input for the process to make sure we're answering (all) the questions," he says.
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