Languages

Global menu

The Green pages

European Earwig

Ravageurs et maladies
English
Common earwig (Forficula auricularia), adult, male.
Photo: René Limoges

Onglets

Description

Summary

Of the five species of earwigs known in Quebec, European earwigs (Forficula auricularia) are the most common. These nocturnal insects are easy to identify, with the two tiny pincer-like appendages at the tips of their abdomens. They eat a varied diet, ranging from small insects like aphids to spider mites, slug eggs and plant litter. They can also damage plants (young shoots, leaves, flowers and ripe fruit and vegetables) when present in large numbers.

Signs and symptoms

  • A plant that has been attacked by earwigs has leaves full of holes and ragged flowers.
  • Ripe fruit and vegetables are full of holes, with insects hiding in them; in some case, young shoots are devoured completely.
  • The damage may often be confused with that caused by slugs. Unlike these molluscs, however, earwigs do not leave slimy trails.
  • These insects may also transmit viruses to plants.

Latin name (genus)

Forficula auricularia

Host plants

Various ornamental plants, including aster, carnation, chrysanthemum, clematis, dahlia, gladiola, marigold, pansy, rose, rudbeckia, sunflower and zinnia.

Fruit and vegetables, including bean, beet, cabbage, carrot, celery, corn, lettuce, pepper, potato, rhubarb and strawberry.

Development cycle

Description and life cycle

These chewing insects belong to the order Dermaptera. They undergo incomplete metamorphosis (hemimetabolic insects). Their life cycle includes three distinct stages: egg, larva and adult.

Eggs: Pearly white, smooth and ovoid.

Larvae: Similar to adults, only smaller (2 mm) and greyish.

Adults: Elongated and flattened, shiny, brownish-red bodies. They are about 2 cm long. They have two long antennae on the head and chewing mouthparts. They have six slender legs on the thorax and two pairs of small wings, which they rarely use. They have two pincer-like appendages (cerci) on the abdomen; males have large, curved cerci and females have small, nearly straight ones.

Earwigs reproduce sexually. Males and females mate primarily in July and August.

In fall, as soon as there is regular nighttime frost, adults burrow into the ground for the winter. Most males die over the winter, but females survive until June.

Between mid-November and mid-December, each female lays about 50 eggs in a burrow in the soil. She watches over the eggs until they hatch (in mid-May) and then cares for the young larvae for two or three weeks, until their first moult. In late May, the young leave the burrow at night in search of food, returning during the day. Soon they leave the burrow and seek out other dark sheltered spots in which to hide during the day.

The larvae progress through four moults before reaching the adult stage. In Quebec, the first adult earwigs usually appear in July and are active until October. There is a single generation each year.

Prevention and control

Favourable conditions

Earwigs establish themselves and proliferate in cool, damp spots near a food source. They are attracted by decaying plant matter.

Identification

Earwigs are very active at night, but can also be spotted around dawn and at dusk. In daytime, look for them in damp, dark corners: under plant litter, in hollow stems and flower buds, inside ripe fruit and vegetables, in cracks in foundations, sidewalks and window frames, in the hollow legs of lawn furniture, etc.

Prevention

  • Keep plants healthy by fertilizing them properly and watering them during dry spells.
  • Apply organic mulch (compost, buckwheat, etc.) to plant borders. Organic mulch provides shelter for earwigs' natural predators.
  • Eliminate potential hiding spots (piles of wood or stones, litter, etc.).
  • Remove all dead and fading plant parts regularly; harvest fruit and vegetables before they rot.

Physical control

Install traps near host plants. Remove traps early in the day and drown insects in soapy water.
Examples of traps:

  • rolled up, damp newspaper, coated in peanut butter
  • tin cans filled with fish oil or vegetable oil
  • overturned flower pots filled with damp newspaper
  • lengths of old hose or bamboo stakes

Rake the soil in fall to expose the insects to predators and severe weather.

Biological control

  • Earwigs have many natural predators (spiders, beetles, centipedes, toads, birds, etc.). Encourage them by growing a wide variety of plants.

Chemical control

As a last resort, use a low-impact pesticide with insecticidal soap or silicon dioxide (diatomaceous earth) as the active ingredient. Read the product label carefully and follow the manufacturer's recommendations.

Further reading: Earwigs in Insects and other arthropods.

Add this

Share this page