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To: Anthony Wong who wrote (2366)	8/5/1999 11:05:00 AM
From: SteveR	Read Replies (1) \| Respond to of 2539

National Cotton Council Reaffirms That Bt Cotton Resistance Management for Pink Bollworm is Sound ====================================================================== MEMPHIS, Tennessee, Aug. 4 /PRNewswire/ -- The National Cotton Council (NCC) today said it remains convinced that current resistance management strategies for pink bollworm -- including the use of refugia -- are appropriate and reaffirmed its commitment to preserving the effectiveness of Bt cotton. Bt cotton contains a gene transferred from the bacterium Bt (Bacillus thuringiensis) that lets plants produce a safe, natural insecticide. When pink bollworm and certain other caterpillar pests of cotton feed on these plants, they die. Dr. Frank Carter, NCC's manager, pest management, said there has been no demonstrated resistance to Bt in pink bollworm populations in the field. He said cotton growers recognize the threat of resistance and currently set aside a portion of their crop in non-genetically modified varieties (refugia) to ensure that the Bt product maintains its effectiveness. This resistance management strategy is based on a collaboration among scientists from leading universities and the USDA's Agricultural Research Service, and has been approved by the U.S. Environmental Protection Agency. The NCC's affirmation of Bt and the use of refuges comes after a recent University of Arizona laboratory study, summarized in the journal Nature (Aug. 5, 1999) suggests that resistant pink bollworms develop more slowly on Bt cotton. "This (Arizona) laboratory study infers that delayed development would somehow interrupt the randomness of mating of resistant moths surviving the Bt cotton with the susceptible ones in the non-Bt cotton refugia," Carter said. "While NCC supports research that contributes to our knowledge base on pink bollworm, these findings must be studied more thoroughly under field conditions. It is premature to conclude that deployment of refuges is not an effective resistance management strategy." Carter, an entomologist, said, "in a field situation, the cotton plants, along with tens of thousands of insects and plants are on different development schedules. Pink bollworms moths emerge, mate and reproduce every day from early spring to mid-summer, consequently, there will be ready supply of susceptible moths present if any resistant moths emerge. This supports the position that the refuge system is a valid strategy for resistance management in pink bollworm. "This information (Arizona study) is encouraging in that this is further evidence that Bt resistance is recessively inherited and secondly, that the refuge strategy will work by countering delayed development of resistant moths by providing a continuous daily supply of moths to mate with those surviving the Bt cotton. This is good news." Chuck Youngker, chairman of the Arizona Cotton Growers Association, said, "Bt cotton is a very important technology for our members. We believe in insect resistance management, and we're committed to doing whatever it takes to continue receiving the benefits it provides."