Earwigs: Identification, Control & Prevention

Earwigs (pincher bugs, Dermaptera) are nocturnal, fast, and hide by day in dark, damp places (decaying wood, basements, woodpiles). They eat aphids, maggots, armyworms—beneficial—but also damage plants. Ancient order (208 MYA); 1,100 species worldwide except poles. North America's common species (Forficula auricularia) arrived with European immigrants.

Social: congregate in thousands, non-territorial. Males have long curved cerci (pincers); females shorter, straighter. Pincers for defense, prey capture, mating—not biting humans.

Identification

• 3/4", reddish-brown, forceps-like cerci at abdomen.
• Two wing pairs; pincers help unfold wings; rarely fly.
• Diet: decaying material, but attack living plants (flowers, lettuce, celery, fruit).
• Females lay 40–50 eggs in underground tunnels; hatch ~1 week.
• Nymphs resemble adults; 10 weeks to maturity.
• Hide under pots; eat pot flowers.

Damage

• Jagged, holey leaves; ragged overnight; partial consumption.
• Black excrement scattered.
• Worse after rain (forced up into plants).
• Found under damaged plant pots.

Control

• Bamboo/hose traps between plants; check mornings; dump in soapy water.
• Petroleum jelly on stems—won't cross.
• Borax on woodpiles (keep pets/kids away).
• Oil pit traps: soy sauce + vegetable oil in container with lid holes; bury to holes; change as needed.
• Alcohol spray: equal parts 70% alcohol + water (or 1:1.5 for 95%); penetrates waxy coat.

Prevention

• Expect more in rainy years.
• Avoid susceptible plants near ivy/hedges (earwig habitat).
• Birds and toads are predators—encourage them.
• Check items brought indoors (laundry, furniture, firewood). Move mulch from foundation; create bare soil buffer. Vacuum indoor strays.

Plants Affected

• Shasta Daisies
• Lettuce
• Dahlias