Earwigs
The European earwig is a flat, reddish-brown insect about ½ inch long, with pincers at its tail. It is both a pest and a predator. At night it chews ragged holes in petals, seedlings and soft fruit, and eats corn silks. By day it hides in dark, damp crevices. It also eats aphids and insect eggs, and in apple and pear orchards it is a valued predator of woolly apple aphid and pear psylla. Its pincers are harmless to people. Most gardens can leave earwigs alone. Where they damage plants you care about, trap them in rolled newspaper or oil-baited cans, and clear away the damp cover they hide in.
Male Forficula auricularia, with curved forceps, on a chewed dahlia flower. Photo: pending.
Identification
Adults are 13–15 mm (about ½ in) long, not counting the forceps (UF/IFAS, RHS); Minnesota gives ⅝ in and UC IPM about ¾ in. They are flattened and dark reddish brown, with very short wing covers and a pair of forceps (cerci) at the tail. In males the forceps are strongly curved. In females they are nearly straight. The University of Minnesota says the forceps can grab but cannot squeeze hard, and that earwigs are harmless to people.
The European earwig is the common one in gardens across the northern US and Canada. It was first recorded in North America in Seattle in 1907, and had spread to most northern states by the 1930s and 1940s. UF/IFAS says it is unlikely to become abundant in the southeastern states, although Clemson finds it the most common earwig in South Carolina, alongside the southern ring-legged and striped earwigs. In the UK, the small lesser earwig (Labia minor), about 6 mm long, lives in compost heaps and does not damage plants.
Easily confused with
- Slugs and snailsAlso a pestThe ragged holes look alike, but slugs and snails leave silvery slime trails and earwigs leave none. Check with a torch after dark.
- Cutworms and other caterpillarsAlso a pestCaterpillar feeding comes with webbing, droppings (frass) or pupae nearby; earwigs leave none of these and are seen on the plant at night.
- Rove beetlesBeneficial — leave itRove beetles share the long body and short wing covers, but they have no forceps at the tip of the abdomen.
- Striped earwigHarmlessThe striped earwig (Labidura riparia) occurs in southern California and the South. UC IPM says it does not damage plants, and Clemson calls it a beneficial predator; the plant feeder is the European earwig.
Damage symptoms
Earwigs feed at night, so the damage appears overnight and nothing is seen by day. UC IPM warns that the leaf damage can look like caterpillar feeding. Look for webbing, frass or pupae, which mean caterpillars. Look too for slime trails, which mean slugs or snails. UF/IFAS adds that earwigs in harvested produce may matter more than what they eat, because most people find them and their smell repellent.
- Ragged holes in the petals of dahlias, zinnias, marigolds, clematis and chrysanthemums
- Chewed seedlings
- Many irregular holes in leaves, or leaves chewed from the edges; in bad cases older leaves are reduced to a network of veins
- Shallow gouges or deep holes in apricots and other stone fruit, and damage to strawberries, raspberries and blackberries
- Chewed corn silks and poorly filled ears
- Earwigs sheltering in fruit already opened by birds, snails or cutworms
Lifecycle & degree days
There is one generation a year. Adults overwinter in pairs in cells in the soil. The female lays her eggs there in autumn or winter, guards them, and feeds the young nymphs until their first moult. Some females lay a second, smaller batch in spring or early summer. In Minnesota, nymphs leave the nest from late May to early June and become adults in late June or early July. The RHS says earwigs are most active from May to September. In the hottest parts of California they are fairly inactive in summer, and in mild coastal climates some stay active all year.
- Eggs
- 30–60 in the first batch; a second batch has about half as many
- Hatch
- 56–85 days for winter batches (British Columbia); about 20 days in spring
- Nymph instars
- Four
- Generations / yr
- One (some females lay two batches)
- Overwinters
- Adults, in pairs in the soil
Host crops
Earwigs eat almost anything soft. UC IPM and the RHS single out seedlings, soft fruit, sweet corn silks, and the flowers of dahlias, zinnias, marigolds, clematis and chrysanthemums. Minnesota adds butterfly bush and hostas. UC IPM says earwigs do not harm hard fruit such as apples. The RHS says that on fruit trees they give good control of fruit aphids without damaging the trees or the fruit. Apple and pear are listed here because that is where earwigs are most useful.
Monitoring & action thresholds
No extension source gives a numeric threshold for earwigs in gardens. The first question is whether they are doing the damage at all: UC IPM's check is to go out at night with a torch and watch. The RHS advises tolerating them as part of the natural balance, and on fruit trees they are an asset. Act where they are damaging something you care about, such as seedlings, dahlias, soft fruit or corn silks, and only around those plants.
Traps double as monitors. At dusk, lay rolled-up newspaper, corrugated cardboard, bamboo tubes or short lengths of hose on the soil near damaged plants. The RHS uses upturned pots loosely stuffed with hay or straw on canes. Shake the traps out into a bucket of soapy water in the morning. Oil traps also work. UC IPM uses a low-sided can, such as a tuna or cat-food can, sunk to its rim with ½ inch of fish oil, or vegetable oil with a drop of bacon grease. Keep trapping daily until the catch stops.
Biological control
Earwigs are predators themselves. UC IPM calls them voracious feeders on aphids and insect eggs, and UF/IFAS puts their diet at roughly equal parts plant and animal matter. The evidence is strongest in orchards. In a Spanish organic-apple trial, releasing 30 earwigs per tree each year shortened woolly apple aphid colonies from the second year onwards. In a Washington State study, earwigs trapped in stone fruit and released in apples and pears reduced woolly apple aphid and pear psylla. Not every trial worked: releases in French orchards did not reduce rosy apple aphid. Earwigs have enemies of their own. UC IPM mentions toads and birds. The tachinid fly Bigonicheta spinipennis has been reported to parasitise 10–50% of earwigs in British Columbia, and fungi infect them in cool, wet regions. No beneficial insect is sold to control earwigs.
Cultural controls
The extension sources recommend trapping and removing shelter. Be clear about what trapping does. It protects particular plants, but in a two-year Washington State study, mass trapping with rolled cardboard neither reduced earwig numbers in stone fruit orchards nor substantially reduced fruit damage. Trap where the damage is, and leave earwigs alone elsewhere.
- Trap nightly beside the plants being damaged, using rolled newspaper, cardboard, bamboo, hose or straw-filled pots on canes. Empty the traps into soapy water each morning
- Sink tuna or cat-food cans to the rim with ½ inch of fish oil, or vegetable oil with a drop of bacon grease
- Remove daytime shelter near vulnerable plants: boards, debris, dense ground cover, vines and weeds. Thin heavy mulch
- Water by drip irrigation to keep the surface drier
- If earwigs damage soft fruit, band the trunks with a sticky barrier such as Tanglefoot. Keep suckers, weeds and brush away from the base, and pick fruit as soon as it ripens
- On apples and pears, encourage earwigs: the RHS suggests flower pots loosely stuffed with hay in the trees
- Indoors, sweep or vacuum up stray earwigs and seal gaps around doors and windows. They do not breed indoors
- If you must use a product, UC IPM rates spinosad baits (such as Sluggo Plus) or spinosad sprays as the most effective and environmentally sound, though baits often work poorly where other food is plentiful. Put baits around susceptible plants before they are infested and apply at night. Spinosad is very highly toxic to bees until sprays dry, so never spray open flowers
Chemical, last resort
Sources
UC IPM Pest Notes 74102, Earwigs (Flint, rev. 10/2012)
UF/IFAS Featured Creatures (IN875), European Earwig, Forficula auricularia (Capinera)
University of Minnesota Extension, Earwigs (reviewed 2024)
RHS Advice, Earwigs
Clemson HGIC 2421, Earwigs (Zungoli, Benson & Ridgeway; rev. Huss, 2024)
Hanel et al. 2023, earwig relocation from stone fruit to pome fruit, Insects 14: 906
Alins et al. 2023, earwig releases against woolly apple aphid, Insects 14: 890
Dib et al. 2016, early-season earwig releases against rosy apple aphid, Bull. Entomol. Res. 106: 233
Texas A&M Field Guide to Common Texas Insects, Earwig
NPIC, Spinosad General Fact Sheet (Oregon State University)
Page status
Drafted from the sources below, then checked claim by claim against those sources on 23 September 2026.
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