Integrated pest management, Bt crops, and insecticide use: The U.S. experience

Bt crops have features amenable to IPM systems and their incorporation into such systems has been quite successful in some institutional settings. Widespread adoption of Bt cotton and maize in the United States has contributed to dramatic, unprecedented reductions in insecticide use. When introduced into settings with less-developed IPM systems, however, secondary pest outbreaks and field-evolved resistance have become problems. Pest resistance to Bt has yet to become a serious problem in the United States but remains a concern. A major industry response to potential resistance and grower non-compliance with resistance management regulations has been development of pyramided Bt varieties and seed mixtures. These address some immediate problems, but may take some discretion in pest management away from growers. IPM principles that recognize the biological complexities of pest management may prove essential for sustaining the benefits of Bt crops.