Bagworm Threat to Evergreens: When to Act

Risk Level

Bagworms can kill conifers if they cause complete defoliation for two or more consecutive years. Typically, they cause partial dieback.

Control Options

• Hand-picking: Remove and destroy bags (best in fall/winter before eggs hatch).
• Spraying: Apply acephate (Orthene) to foliage when larvae are active (late spring/early summer).

Timing Matters

Early intervention prevents severe defoliation. Monitor evergreens annually for the characteristic spindle-shaped bags.