Managing the Risk of European Corn Borer Resistance of Transgenic Corn: An Assessment of Refuge Recommendations

Industry and scientists have worked to develop a high-dose refuge management plan that can effectively delay European corn borer (ECB) resistance to new genetically modified pesticidal corn. For a high dose, the corn expresses enough pesticide to kill all but the most resistant corn borers. For refuge, producers plant a traditional corn variety that allows susceptible corn borers to thrive and mate with resistant corn borers, slowing the proliferation of resistance. In general, the more refuge that is planted the less likely resistance. While there is general agreement on the basic premise of the high-dose refuge plan, how much refuge is needed to manage resistance is still being debated. This paper develops a stochastic agricultural production model to assess and provide insight into the reasons why refuge recommendations remain controversial. We find that (a) reducing the risk of resistance requires decreasing agricultural productivity, (b) new technologies that are currently being tested will reduce the risk of resistance, (c) producer noncompliance increases the risk of resistance, and (d) nonrandom mating in the ECB populations increases the risk of resistance. Disagreements over the importance of nonrandom mating and producer compliance can be resolved with additional research. Controversy will remain, however, as long as producers and industry continue to bear most of the financial cost of reducing the risk of resistance through higher refuge recommendations.