Corn rootworm is a major corn pest in the United States and established throughout Iowa. With the commercial release of transgenic Bt-rootworm corn in 2003, many farmers reduced or eliminated soil-applied insecticides to manage larvae. However, western and northern corn rootworm are adapting to transgenic technologies throughout the Corn Belt. This publication will review the current status of Bt resistance by rootworm in Iowa and recommend management strategies for sustainable corn production.