Control of the Forest Tent Caterpillar With Microbial Agents

The forest tent caterpillar, Malacosoma disstria Hubner, is a defoliator of many species of trees and shrubs in forested areas. When it increases to outbreak proportions, host plants in large areas are often denuded. Caterpillars are a source of irritation to humans when the larvae and their droppings fall on them and their food. The article discusses an investigation performed to determine if a practical degree of caterpillar control could be obtained with microbial control agents, primarily the bacterium, Bacillus thuringiensis Berliner. Both chemical and biological agents were used in replicated laboratory and field tests for control of ,the forest tent caterpillar, Malacosoma disstria Hubner. All of the control agents used in these tests except the virus material provided significant reductions in caterpillar numbers