Involvement of Potential Participant Groups

The designated public comment period on the petition ended, with no submissions, on April 29, 1997. There was no indication from the documents of any other public involvement.

Two Bt Corn Petitions

Background

Insect pests of corn (Zea mays L.) comprise members of many different orders, including seed maggots, rootworms, wireworms, grasshoppers, flea beetles, aphids, and leafhoppers, which feed on kernels, roots, leaves, silks and vascular tissue (Hill 1983, 1987; Davidson and Lyon 1987; Straub and Emmett 1992; Steffey et al. 1999). Some leafhoppers and aphids are vectors for plant pathogens. The main Lepidopteran pests of field corn in the United States are borers (European corn borer, ECB, Ostrinia nubilalis (Hübner); southwestern corn borer, SWCB, Diatraea grandiosella, and corn earworm, CEW, Helicoverpa zea (Boddie) and defoliators (e.g., armyworms). Some of these pests are a chronic problem; others periodically account for severe yield losses (e.g., Ostlie and Hutchison 1997, Mississippi State University Extension Service 1999).

According to various extension service fact sheets for corn growers (Mississippi State University Extension Service 1999, Swanson 2000, University of Illinois 2001), management options for pest control include (1) early planting; (2) crop rotation; (3) resistant varieties; (4) varieties that attract natural enemies of target pests; (5) soil quality management; (6) noncrop management to reduce alternate hosts for pests, e.g., barnyard grass for armyworms, and to enhance naturally occurring predators and parasitoids; (7) conservation of natural enemies through intercropping or insectary plantings of noncrop vegetation; (8) augmentation (field releases) of natural enemies (e.g., Trichogramma spp. egg parasitoids); (9) destruction of corn stalks after harvest; and (10) insecticide treatments. Organically managed corn in the Midwest relies primarily on crop rotation for pest control (Swanson 2000). Price premiums compensate for lower yields under organic management. A relatively small proportion of the total U.S. field corn acreage is treated with insecticides, in part because sprays are often not a reliable or cost-effective means of controlling some of the major pests. For example, less than 5% of U.S. field corn acreage was sprayed for ECB before adoption of Bt corn (Gianessi and Carpenter 1999).

Genetically based pest resistance in corn was developed through the use of conventional breeding methods utilizing mechanical, chemical-repellent, or antibiotic properties of the corn plant. Commercial varieties



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