The European corn borer, Ostrinia nubilalis (Hubner), is a pest of corn throughout the Corn Belt. It also is the target pest of the first commercially available transgenic corn hybrids. These transformed hybrids contain a modified gene from the bacterium Bacillus thuringiensis Berliner that expresses an insecticidal protein (Koziel et al. 1993, Bio!T echnol. 11 : 194-200). The widespread use of these hybrids has fueled the development of resistance management models and protocols.