Each year, the larvae of the pink bollworm cause more than $7 million in damage to the U.S. cotton crop. Now, in the first open-field release of a genetically modified insect, entomologists hope to show that genetically engineered versions of this small moth could help control or even eliminate this major pest. Not only could the project protect the nation's approximately five million hectares of cotton crops, but it could clear the way for the testing of other genetically modified insects as a more effective and environmentally benign alternative to pesticides.

The U.S. Department of Agriculture has approved plans by its scientists to conduct a full field release of the biotech bollworm in the summer of 2005, following several years of tests in enclosed fields. In this trial, the insects will contain only an extra gene that makes them fluoresce under ultraviolet light, allowing researchers to distinguish the laboratory-bred bugs from wild bollworms. "We're trying to see how the transgenic animals behave in the field," says University of California, Riverside, entomologist Thomas A. Miller, who led the effort to modify the insects.