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Spruce budworm (Western)

Choristoneura freemani

15 host plants

Last updated

Data Coverage 1 of 6 dimensions
Host Plants
GDD Threshold
Peak Activity
Damage Severity
Monitoring
Regional Notes

Look for brownish or reddish-tinged foliage on true firs in late summer, particularly at higher elevations. The western spruce budworm larvae tie new shoot tips together with webbing, feeding on buds and emerging needles. Most common on Pacific silver fir, grand fir, and white fir. Affected branches and tree crowns take on a scorched appearance by August.

For landscape trees, this is primarily a visual concern. Preserve natural parasitoid populations. Prune lightly infested branch tips in late spring. Natural rainfall and cool temperatures support recovery. No pesticide applications are typically needed for ornamental trees.

Quick Reference

Order
Lepidoptera
Type
defoliator
Host Plants
15

Host Plants (15)