Plants modified with protectant genes designed to kill resistant insects can extend the usefulness of currently used pest-control methods and delay the development of pesticide-resistant bugs, according to Purdue University scientists and their collaborators from the University of Wisconsin-Madison, Monsanto Co., the University of Illinois and the University of California, Davis. The researchers' findings appear in this month's issue of the Journal of Theoretical Biology.

"We always thought that it would take a Michael Jordan of toxins - a superstar of toxins to effectively halt insect resistance to the current generation of insecticides," said Barry Pittendrigh, a Purdue associate professor of entomology and lead author of the study. "We found that moderately effective genetically engineered protectants used in plants in the buffer zone around the main crops can play a major role in insect control, and they should be easier to identify than highly effective protectants.

"You don't find a superstar very often, but it may not be difficult to find good players, or worthwhile insect-control agents."

Farmers who use bioengineered crop protectants also use a buffer, or refuge, around the outside of fields that contains plants lacking the high-toxicity genetic modification in the main field that kills most insects. The refuge, usually about 20 percent of the acreage planted, delays development of insects resistant to the main-field, high-toxicity protectants, but some individuals in the destructive insect group have genes that allow them to survive.

Using a computer model, the scientists determined that within a refuge, one could add a moderate plant protectant, or journeyman player, that kills 30 p
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Contact: Susan Steeves
ssteeves@purdue.edu
765-496-7481
Purdue University
25-Oct-2004