UC Davis researchers have created a more potent natural insecticide aimed at agricultural caterpillar pests, by inserting into an insect virus a gene that causes the virus to manufacture an insect-specific toxin found in scorpion venom. In laboratory tests, the genetically engineered virus acted much more quickly than the naturally occurring virus in causing caterpillar larvae to stop feeding, exhibit symptoms of paralysis and die. "Biological insect controls are desirable alternatives to chemical pesticides because they don't pose the environmental and health risks normally associated with chemical residues," says entomology graduate student Bill McCutchen. "But until now, these viruses haven't been competitive with chemical insecticides because the viruses act much more slowly," he says. McCutchen worked with Bruce D. Hammock, professor of entomology and environmental toxicology, and Susumu Maeda, associate professor of entomology, to engineer an effective recombinant virus that could be orally transmitted to the caterpillars. "We hope that the development of a more efficient, faster-acting virus will provide a unique method for controlling agricultural insect pests," McCutchen says. He stresses that the viruses are very selectively targeted against specific insects and have been shown to be incapable of infecting mammals. McCutchen will report on the recombinant virus at 9 a.m. on Wednesday, Dec. 11, during a talk titled "Development of a Recombinant Baculovirus Expressing an Insect-Specific Neurotoxin: Potential for Pest Control." (At 4:40 p.m. on Monday, Dec. 9, Hammock willl discuss development of a new recombinant virus that produces an enzyme that infects and quickly kills insect pests. At 4:20 p.m. on Wednesday, Dec. 11, Maeda will discuss the roll of genetically engineered proteins for control of pest insects.)