Questions have arisen concerning the current Insect Resistance Management (IRM) strategies for European corn borer in Bt transgenic corn in areas with a history of high insecticide use. Specifically, would insecticide use patterns in areas that routinely treat for corn arthropod pests significantly affect the ratio of Bt susceptible to Bt resistant European corn borers in a manner that compromises the current high-dose/refuge IRM strategy? To address this question, a crop consultant survey was developed to collect information on insecticide use on Bt and non-Bt corn in the Western Corn Belt. Data was gathered and analyzed from three subgroups that reflect common agricultural practices and insect complexes (Southwest, West, East). The consultants reported that relatively few acres were treated with insecticides (£14.2%) during the early whorl stage across the three regions. There was a trend suggesting that non-Bt corn received more insecticide treatment than did Bt corn. The trend during late- whorl stage across regions was for few dryland acres to be treated with insecticides (£12.4%) and for non-Bt corn to receive more insecticide treatment than Bt corn. In the irrigated corn, the difference in insecticide usage between non-Bt and Bt corn was approximately 26, 6, and 19 % in the southwest, west and east regions in 2002, and approximately 20, 12, and 12% in the southwest, west and east regions during the previous five years. This is some of the first data that actually documents that the use of Bt corn can reduce insecticide usage.