Bagworms on Blue Spruce: Too Late to Spray, Plan for Spring

Your 10-ft blue spruce is mostly defoliated by bagworms; bags remain. House for sale; husband wants to cut it.

Current Status

• Caterpillars likely pupated/laid eggs in bags. Spraying now useless.
• If any green tips remain, tree may survive.

Options

1. Keep: Tell buyers tree will refoliate next spring; they must spray Bacillus thuringiensis (Bt) in late May/June when larvae hatch.
2. Cut: If curb appeal is critical, remove and replace.

Spring Plan (If Keeping)

• Scout in late May: look for tiny larvae crawling.
• Spray Bt (Dipel, Thuricide) or spinosad—safe, effective on young larvae.
• Repeat in 7–10 days.

Bottom Line

Too late for this year. Decision: disclose and plan spring spray, or remove for sale.