The European corn borer is one of the most damaging insects in Iowa cornfields, causing more than $100 million in crop losses each year. In this project, the sex attractant pheromone of the European corn borer was used to obstruct the ability of the adult male moths to locate females for mating. In the first year, efforts focused on mating disruption in a small area, while in the second year dispensers were deployed on a larger scale and evaluated for efficacy.