Date: 3/31/99

Time: 10:45

Type: Symposium

Number: 236

Transgenic insecticidal cultivars and corn rootworms: Resistance management considerations

*M.E. Gray, Department of Crop Sciences, University of Illinois, Champaign, IL 61820
Contact e-mail: m-gray@uiuc.edu

The commercialization of transgenic insecticidal cultivars for corn rootworms (Diabrotica spp.) is anticipated within the United States soon after the turn of the century. A Wall Street Journal article (August 21, 1998) indicated that Monsanto Co., pending the satisfactory completion of regulatory requirements, intends to bring to the market transgenic cultivars for corn rootworms by 2001 or 2002. Other companies such as Pioneer Hi-Bred International Incorporated (in cooperation with Mycogen Corporation) and Novartis AG also were reported to be testing transgenic "rootworm" cultivars. If these scientific and commercial efforts are successful, American corn producers will have a new pest management tool at their disposal that can be aimed at a very destructive complex of insect pests, corn rootworms. Adoption of corn rootworm transgenic hybrids is expected to be much greater than has occurred for Bt hybrids for the control of the European corn borer [Ostrinia nubilalis (Hübner)]. The primary concern regarding the commercialization of transgenic cultivars for corn rootworms is the potential development of resistance. The development and implementation of resistance management plans will be critical to prolong the benefits of transgenic rootworm cultivars. Several features of the corn rootworm life cycle will require closer scrutiny and consideration before effective resistance management plans can be recommended, such as, but not limited to: 1) range of larval mobility between roots of grasses (Setaria spp.) and transgenic plants, 2) adult mobility, 3) host range of larvae and adults, 4) emergence patterns of adults, and 5) susceptibility differences among larval instars to transgenic insecticidal proteins.

This abstract may not be cited or reproduced without permission from the author(s).