Satin moth

Pale to medium gray-brown caterpillars with distinctive white or yellowish double patches along the back and tufts of hairs on the sides feed on poplar and aspen foliage in Western Washington. Young larvae skeletonize leaves leaving only veins; third instar larvae (reaching 2 inches long) completely consume foliage, causing severe defoliation in June when the tree canopy appears to thin dramatically.

Third instars emerge in late April and feed heavily until pupating in mid-June. Monitor new growth in May for skeletonized leaves. Bacillus thuringiensis (Bt) on early instars provides excellent control without harming beneficial insects. Maintain tree vigor to support recovery.