Potential Benefits of Transgenic Bt Corn for Management of Corn Rootworms
Corn, Zea mays, is widely produced in the United States and it accounts for more than 90% of the total value and production of U.S. feed grains (Economic Research Service 2002). Corn is attacked by a variety of insect pests that can significantly reduce grain yield. Two of the most important pests are the western corn rootworm, Diabrotica virgifera virgifera, and the northern corn rootworm, Diabrotica barberi. The Agricultural Research Service (2001a) estimates that corn rootworms cost farmers nearly $1 billion annually in crop losses and control costs. Current corn rootworm control strategies designed to prevent grain yield losses require the use of insecticides or rotation of corn with another crop. Both of these methods are used widely in the Corn Belt but each has its limitations and has occasionally failed to prevent yield loss derived from insect damage. The future of corn rootworm management may include planting of genetically- engineered corn that resists insect damage and protects grain yields. This article examines information on corn rootworms, current management strategies for their control, and the potential benefits of managing these pests with genetically-engineered corn.