Identification: the earwig you have in BC
The earwig in Metro Vancouver gardens and homes is almost certainly the European earwig (Forficula auricularia), an introduced species now dominant across BC and the entire Pacific Northwest. Adults are 12–15 mm long, dark brown, with a distinctive pair of forceps (cerci) at the abdomen tip. Male forceps are strongly curved; female forceps are straighter. These pincers look alarming but are used for defence and mating display — they rarely break skin and carry no venom. Earwigs are nocturnal, spending days in tight, dark, damp hiding spots and emerging at night to feed. The native BC earwig species (Labidura riparia, the shore earwig) is larger (20–25 mm) and found near coastal or riparian habitats, not in garden beds or homes. If you're seeing earwigs indoors in Vancouver or Surrey, it's F. auricularia.
| Symptom | European Earwig | Slug | Cutworm |
|---|---|---|---|
| Leaf holes | Ragged, irregular, often from edges | Smooth-edged, any location | Large irregular holes or cut-off stems |
| Flower petals | Small notches and holes in petals | Mucus trails present | Less common target |
| Active time | Night only | Night, damp conditions | Night only |
| Evidence left | No mucus trail, frass near damage | Mucus trail always present | Cut stems at soil level |
| Favourite targets | Dahlias, marigolds, basil, strawberries | Hostas, lettuce, seedlings | Tomato stems, brassica seedlings |
| Damage season | June–September in BC | Year-round in BC | May–July in BC |
Garden damage: what earwigs actually eat
Earwigs are omnivores. In the garden they eat aphids, mites, and soft-bodied insect eggs — genuinely beneficial. But they also eat flower petals (dahlias, marigolds, chrysanthemums, and zinnias are favourites), soft fruit (strawberries, raspberries), seedlings, and leafy herbs including basil. The characteristic earwig damage is ragged holes in petals, notching from the edges of leaves, and in heavy infestations the complete defoliation of tender annuals. In BC's kitchen gardens, earwig pressure peaks in June through August. They're especially damaging to ornamental borders and dahlia collections — a single earwig can notch dozens of petals in one night. The practical threshold: if more than 20–30% of flowers show petal damage and earwig counts under a damp board trap exceed 10–15 per night, control is warranted.
Why earwigs enter BC homes
Two weather patterns drive earwig entry into Metro Vancouver homes. First, extended dry summer spells: outdoor earwig populations lose moisture and actively seek it, moving toward cooler, damper areas including basements, crawlspaces, and under-slab zones. Second, heavy autumn rain following a dry period: saturated outdoor soil forces earwigs to seek elevated, dry shelter. They enter through door gaps, basement window frames, utility penetrations, and poorly-fitted weatherproofing. Indoor earwigs are almost always a perimeter problem — they congregate near the entry point, in basement corners, or under laundry appliances. They rarely establish reproducing indoor populations because the relative aridity of heated indoor spaces doesn't suit them. Most indoor earwig events are resolved with exterior treatment and sealing, with no interior chemical application needed.
Earwig control — garden and perimeter protocol
The integrated protocol for managing earwig damage in BC gardens and preventing home entry. Addresses both the garden pest and the occasional indoor invader.
- 1Assess garden damage and set monitoring trapsPlace corrugated cardboard traps or damp newspaper rolls near affected plants. Check at dawn. Count earwigs per trap to gauge population density. Also check under mulch and leaf litter within 1 m of the foundation for earwig concentrations.
- 2Reduce exterior harborage near foundationClear leaf litter, dense mulch layers, and woodpiles within 1 m of the foundation. Move potted plants away from the building perimeter. Lift boards, stepping stones, and landscape timbers that provide daytime refuge adjacent to the home.
- 3Apply targeted perimeter granulesApply a granular pyrethroid product (registered for outdoor use, earwig-labelled) at the foundation perimeter in a 30–60 cm band. Water in lightly. Effective for 30–60 days; reapply after significant rain. Do not apply to areas with ground-foraging birds or where pollinators land.
- 4Seal structural entry pointsReplace or adjust door sweeps and thresholds. Weatherproof basement windows. Fill foundation cracks with polyurethane caulk. Seal utility penetrations with mesh and foam. Focus on the 15–30 cm above-grade zone where earwig entry concentrates.
- 5Garden bed management — reduce earwig habitatReplace thick organic mulch within 60 cm of edible or ornamental beds with coarser bark chip or gravel that dries faster. Hand-pick earwigs from trap sites at dawn and destroy. For dahlia or chrysanthemum collections, apply targeted spinosad spray to soil and stem bases at dusk during high-pressure periods.