Biotech Cotton Curbs One Pest Only to Unleash Another

Genetically engineered crops are becoming victims of their own success. Over the past decade, cotton modified to produce a toxin lethal to its most pesky insect predator has revolutionized the industry. From the U.S. cotton belt to northern China, farmers have found that with their primary foe neutered, they have been able to dramatically cut their insecticide use--at least, for a time.

While some U.S. growers have cannily integrated the crop, known as Bt cotton, into pest strategies that have dropped insecticide use by 75 percent, not all farmers have applied the same forethought in adopting the cotton. And these farmers are reaping the consequences, as an echo boom of bugs that had previously been controlled by indiscriminately applied insecticide are beginning to rise again.

Nowhere has this rebound been more problematic than northern China, where a minor pest, the mirid bug, has become a major ordeal. Farmers there widely adopted Bt cotton, which has devastated its target, the bollworm. Pesticide use fell. Few expected the mirid would take advantage of the situation.

Read more from this May 17 New York Times article, which includes quotes from CALS faculty members Peter Ellsworth and Bruce Tabashnik
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Bruce Tabashnik
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Released date: 
Jul 5 2010