Western Spruce Budworm in Utah: Identification, Management, and Control
Utah State University Extension
The western spruce budworm (Choristoneura occidentalis) is a serious defoliator of Douglas-fir, spruces, and true firs in western North America. Its larvae feed on young developing buds, needles, shoots, and other plant parts. Damage varies but can be severe. Control can be accomplished with insecticides on selected trees but is difficult in forest stands.
Kuhns, M.R. 1999. Western spruce budworm in Utah: Identification, management, and control. Utah Div. of Forestry, Fire & State Lands fact sheet. 2 pp.