The European corn borer and Bt corn in the United States

The European corn borer, Ostrinia nubilalis Hubner (Lepidoptera: Crambidae), is an economically important insect pest of corn (Zea mays L.) and other crops in North America and Europe with yield losses up to 20% caused by larval feeding. Damage from larval infestations of corn was estimated to exceed US $1 billion annually in yield losses and control expenditures. It is a cosmopolitan species, originally distributed in Europe and from there introduced into America, where it has now spread to most of Southern Canada and the US east of the Rocky Mountains. Larval feeding on corn plants results in physiological disruption of plant growth and structural damage to the corn plant. Although capable of developing on > 200 herbaceous plant species, O. nubilalis has a strong preference for corn as a host plant. Chemical insecticides often are not effective against O. nubilalis infestations because once the larvae tunnel into the corn stalk they are protected from exposure; thus there is a narrow application window for growers. European corn borers typically have