There are several methods to manage corn rootworms, including crop rotation, rootworm insecticides, and corn rootworm (CRW) transgenic traits. The use of CRW transgenic traits in corn hybrids has allowed farmers to manage CRW without using soil-applied insecticides. However, rootworm populations resistant to the transgenic traits have been confirmed in Iowa, leading some farmers to see if there is an economic return by adding an insecticide when planting CRW-Bt corn. There also are several transgenic traits now available for corn rootworm control on the market. On-farm trials allow farmers to see how these traits perform on their farms in side-by-side evaluations.