Bagworm Management on Blue Spruce in Pennsylvania

Eastern PA property has bagworms on two blue spruces (50 yards apart) with three other spruces nearby. Concerned about spread.

Bagworm Biology

• Spindle bags (1.5-2.5") camouflaged with plant debris.
• Females flightless → populations build locally on preferred hosts (arborvitae, cedar, juniper).
• Spread slowly between trees; usually isolated to adjacent plants.
• Hosts: pine, spruce, cypress, juniper, many deciduous trees.

Control Options

1. Hand-pick bags in late fall (cut silk band to prevent girdling).
2. Bt spray late June (after egg hatch, before ballooning).
3. Chemical: Orthene, bifenthrin, Sevin, etc.—thorough coverage essential (bags protect larvae).

Controlling current trees likely prevents spread to others due to limited mobility.