Insect Resistance Management and Refuge Requirements for Bt Corn

Bt corn hybrids are genetically modified to contain a bacterium that acts as an insecticide. Insect resistance management (IRM) is used to maintain Bt-susceptible insect populations. The goal of IRM is to prevent or delay the development of insect resistance to Bt traits, and this is accomplished by planting refuge corn acres on each farm where Bt corn hybrid is planted.

This publication addresses: the significance of IRM and planting refuges, who checks for IRM compliance, the refuge requirements for Lepidoptera and corn rootworm protection, selecting the best Bt insect trait package, the lifetime of Bt insect traits, where Bt traits are expressed in the corn plant, and what to do if the Bt corn hybrid doesn’t control the targeted insect (8 pages).