In the summer of 1998 over 2.8 million acres of farmland in the Southern U.S. was planted in genetically engineered cotton expressing a gene derived from the bacterium, Bacillus thuringiensis (Bt). This Bt gene codes for production of a protein that is toxic to some of the most important lepidopteran pests of U.S. cotton. The future expansion of this new technology on more cotton acreage and in other crops is expected to have important environmental and economic benefits.The development of resistance by key pest species to Bt toxins could negate the value of transgenic Bt technology in crop protection. The EPA, industry and many scientists have concluded a system of monitoring Bt resistance is needed. Such a system requires tests that can measure the resistance of insects to Bt toxins in a simple, inexpensive and reliable way. The proposed program is focused at optimizing, developing and validating a novel, practical method for detecting and measuring the resistance of insects to Bt toxins using feeding disruption technology and hydrateable insect meal pads. During the Phase I study, feasibility was demonstrated for this method when testing tobacco budworm and cotton bollworm for resistance to Bt and several chemical insecticides.
Anticipated Results/Potential Commercial Applications of Research:Successful development of the proposed idea will provide a rapid field test for Bt resistance that is simple to read, inexpensive, requires little training to perform and is unaffected by the specific mechanism of Bt resistance. The test is expected to be uniform, reproducible, stable in storage and tolerant of elevated temperatures. It is expected this test format will be very useful to measure insect resistance to chemical insecticides and be applicable to many insects and crops.
