Webworm

Webworm larvae construct loose, silken tents over foliage on spruce branches, trapping debris and fecal material inside. Look for grayish, baggy webbing in branch crotches or on branch tips, typically appearing in mid to late summer. Foliage inside and around the web becomes brownish as larvae feed. Picea species and occasionally fir show damage; purely cosmetic but noticeable.

Prune affected branch tips with webbing intact and discard material in fall before adult emergence. Small populations require no intervention. Do not spray into webs; natural parasitoids and predatory insects suppress webworm populations when pesticides are avoided. For large trees, this damage is negligible and trees recover readily the following growing season.