One might think that it would be possible to call EPA and readily obtain copies of the approved resistance management plans for Bt corn, cotton, and potato. It took UCS weeks to obtain the various documents dealing with the plans. It is still not clear which measures proposed by industry but not mentioned in the official registration documents are considered by EPA to be in the plans. Below we focus on the prevention strategies contained in the resistance plans. We will look at monitoring, mitigation, research gaps, and enforcement in future issues.
Scientists understand why resistance develops to pesticides.
Put simply, chemicals that kill susceptible individuals in a population create opportunities for resistant ones. Killing off susceptible individuals year after year allows resistant individuals to multiply and eventually predominate. Scientists knowledgeable about insect behavior and genetics have suggested a number of approaches to avoid or delay resistance.3 Many of the strategies work by lowering the effective dose of Bt to allow survival of enough Bt-susceptible insects to deprive the resistant organisms of a survival advantage. Below are brief discussions of three approaches that scientists believe might be used to prevent the development of resistance to Bt crops. Use Bt with other unrelated methods of pest control.