Thyridopteryx ephemeraeformis
Lepidoptera: Psychidae
Identification
• Each caterpillar lives in a silk tent up to 11/2" long that is covered
with pieces of brown foliage. (a)
• Adult males are black, 1/2" long heavy-bodied moths with clear wings.
• Adult females are caterpillarlike and stay in the bag.
Damage
• The caterpillars feed on the foliage of arborvitae, eastern red cedar,
juniper, spruce, oak, honeylocust, and many other trees and shrubs.
• Feeding occurs first at the top of the plant in mid to late June.
(b) Fully grown larvae stop feeding in late summer.
• Defoliated conifers will die; deciduous plants will regrow leaves.
Management
• Eggs overwinter in the old female bags. Remove and destroy the bags
between September and mid-June to eliminate the eggs.
• Handpick and destroy the caterpillar-containing bags.
• Bacterial and other insecticides are effective against younger, smaller
caterpillars in late June.