U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


Date of this Version


Document Type



Agricultural Research January 2002


Scientific advancements built on an understanding of what nature already provides are leading to environmentally friendly crop-pest control by either biological agents or specifically designed synthetic antiinsect compounds. A case in point: research on baculoviruses.

Baculoviruses are rod-shaped DNA viruses, many of which begin their life cycle reproducing inside cells. In the nuclei of caterpillar cells infected with baculoviruses, viral progeny multiply and are incorporated into protective polyhedronshaped protein structures called occlusion bodies. Infected caterpillars die and contaminate the leaf surfaces with the occlusion bodies. Then, healthy caterpillars ingest the occlusion bodies and release the virus when feeding on contaminated leaves, thus continuing the life cycle of infection and replication.

“Each year, natural baculovirus epidemics nearly wipe out populations of some caterpillar pests, such as corn earworm, cotton bollworm, tobacco budworm, and cabbage’s nemesis—the diamondback moth,” says ARS microbiologist Arthur H. McIntosh, at the Biological Control of Insects Research Laboratory (BCIRL), Columbia, Missouri. If that assertion doesn’t have a familiar ring to most growers of major U.S. crops, it’s probably because the epidemics occur after crop damage has already been done.