A study was undertaken to determine species composition and seasonal abundance of ground-dwelling insects associated with European corn borer (ECB),Ostrinia nubilalis(Hübner), adult action sites and to determine impact of adult ECB control on nontarget insects in these sites. A total of 24,497 ground-dwelling insects was collected during the 2-yr study. Coleoptera, Orthoptera, and Homoptera accounted for 98% of the total insect fauna. Three predator species were abundant in ECB action sites:Evarthrus alteransCasey,Pterostichus chalcites(Say), andHarpalus pennsylvanicusDeGeer. Carbaryl (2.26 kg [AI]/ha) or fenvalerate (0.1 kg [AI]/ha) applied for adult ECB control had minimal impact on the ground-dwelling insect community. Predator populations were not affected. Role of action sites as a source of predators for Iowa cornfields is also discussed.