How to treat tent caterpillars

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Several larvae species hold the distinction of being collectively referred to as tent caterpillars; the pests are the caterpillar larvae form of the eastern tent caterpillar (Malacosoma americanum), fall webworm (Hyphantria cunea), forest tent caterpillar (Malacosoma disstria) and the western tent caterpillar (Malacosoma californicum). The pests' voracious feeding poses a danger to deciduous trees and shrubs. The insects build visible silken nests upon the host. All species require similar control measures to successfully treat an infestation. Weak trees can easily perish from the severe defoliation caused by the caterpillars.

Prune away tent caterpillar nests using pruning shears or loppers. Hand remove any eggs or live caterpillars that continue to cling to the area where the nest was located.

Place the nests, eggs and caterpillars into a plastic garbage bag. Consider crushing the insects in the bag to successfully kill them or simply seal the bag and dispose of the insects.

Spray webs located high in a tree canopy with a powerful spray of water. Focus the burst of water directly on the nest to knock the webbing, eggs and caterpillars from the tree. Crush any live caterpillars that fall to the ground.

Spray individual tent caterpillar nests using Bacillus thuringiensis. Apply the substance when the tent caterpillars remain small for the most effect. Follow the directions on the label for application instructions.