Western Spruce Budworm
Choristoneura occidentalis
The most widely distributed and destructive defoliator of coniferous forests in Western North America. Adult moths are 12.7mm long with 22-28mm wingspread, gray or orange-brown forewings with distinctive white dots. Larvae develop through six stages, becoming 25-32mm long.
Identification & Symptoms
What to Look For
Potential Damage
Lifecycle
One generation per year throughout most of rangeMoths emerge late July to early AugustFemales lay approximately 150 eggs in masses on needle undersidesLarvae hatch in 10 days but don't feed initiallyOverwinter in silken hibernacula under bark scalesResume feeding in May-June on new growthPupation in silk webs after 30-40 days feeding
Professional Treatment Approach
Monitor for early larval activity in spring
Insecticide applications during active feeding periods
Biological control with natural enemies
Forest management to reduce susceptible stands
Pheromone traps for population monitoring
Maintain tree health to resist damage
Recommended Mauget Products
Imicide
Professional-grade treatment specifically effective against western spruce budworm.
View Product DetailsDinocide
Professional-grade treatment specifically effective against western spruce budworm.
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