Corn rootworm (CRW) is commonly referred to as “the billion dollar bug” as it costs U.S. growers a billion dollars a year in reduced yields and treatment costs (Burchett, 2001). Traditionally, two-year crop rotations were sufficient to control for CRW. However, in recent years a behavioral variant of the western CRW has moved into Wisconsin cornfields. The variant has adapted to traditional crop rotation by laying its eggs in soybeans and other rotated crops, so that economic damage is caused in corn planted the following year. Soil insecticides were commonly used to control CRW in first year corn, but in 2003, rootworm Bt corn became available for western corn rootworm larval control.