Transgenic Bt com has provided unprecedented control of European com borer, Ostrinia nubilalis, without further inputs of less environmentally-friendly insecticides (Caprio et al. 1998). Transgenic com hybrids contain a protein-producing gene derived from Bacillus thuringiensis (Bt) that is toxic to certain insects when it is eaten by the larval stages (Koziel et al. 1993). Farmers had their first opportunity in 1996 to plant transgenic Bt com hybrids that killed European com borers. This protein prevents large amounts of leaf feeding, stalk tunneling and subsequent yield loss caused by European com borer.