Several species of caterpillar create a web or tent in the branches of trees and feed on the tree’s foliage. The caterpillars rarely cause severe damage to trees unless stressed trees are subject to repeated spring defoliation.
Fruit trees, cottonwoods, aspen, ash, and various other species.
Web worm and tent caterpillar can by controlled mechanically by pruning out infected areas or chemically by insecticide treatment on young colonies. However, pruning can often cause more damage to the tree than the web worm or tent caterpillar.