As Biotech Seed Falters, Insecticide Use Surges In Corn Belt
At the University of Nebraska, entomologist Lance Meinke is turning colonies of rootworms loose on potted corn plants that contain different versions of the anti-rootworm gene, to see how well they survive.
The larvae get to feed on the corn roots for about two weeks. The soil from each pot then is dumped into a kind of steel container. If the larvae are still alive, a bright light will drive them into little glass jars filled with alcohol. "They try to escape from the heat," says David Wangila, a graduate student who is managing this experiment.
If the rootworm-fighting genes in the corn are working well, no larvae should emerge.
But some have. Wangila points to one of the little glass jars. Inside, there are three nice plump corn rootworm larvae.
This is not good. Those insects, originally collected from a cornfield in Nebraska, were feeding on corn that contained the first rootworm-fighting gene that Monsanto introduced ten years ago. Technically, it's known as the Cry 3Bb gene.
Meinke and Wangila will compare the survival rate of these rootworms with others that have never been exposed to Bt. They're looking for signs that rootworms in the corn fields of Nebraska have evolved resistance to genetically engineered crops.
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