Bagworm

A Technical Report from The Bartlett Tree Research Laboratories

The bagworm is an unusual caterpillar and serious defoliating pest of many ornamental trees and shrubs throughout the eastern half of the United States. The bagworm receives its name from the bag-like structure constructed from leaf fragments that are bound together with silk produced by the larva. Most of this insect's life is spent within the bag, which serves as a protective structure. Bags blend in with the host and infestations often go unnoticed until significant defoliation has occurred. Removing and destroying the bags can reduce light bagworm infestations on shrubs and small trees. This should be done in the dormant season before eggs hatch.