The registration application is the first for a Bt-corn variety engineered to control beetles. Bt toxins which are specific for moths, in particular, the European corn borer. Corn rootworms do just as their name implies-they feed on corn roots and as a result interfere with the plant's ability to absorb water and nutrients and to remain upright. Until the adoption of corn monoculture in the Midwest, beginning about 50 years ago, corn rootworms were minor pests. In fields devoted only to corn year after year, large populations of rootworms build up-leading to the use of huge amounts of insecticides.
Many farmers control the corn rootworm through crop rotations.
First, some western corn rootworm females have begun laying eggs in soybean fields in the fall. Then, in the spring, when the field is rotated to corn, the larvae hatch and begin feeding on the corn roots. Second, an increasing number of northern corn rootworms exhibit an extended egg diapause, that is, eggs, rather than hatching the first spring after they are laid, may pass through two or several winters before they hatch. Some of these worms may fortuitously encounter corn when they emerge. EPA should postpone consideration of Monsanto's application to register rootworm-protected Bt corn until it has analyzed data submitted under the company's experimental use permit.