Species

Host/Site

Earwigs are common in gardens, landscapes, and field and orchard crops. They are most active at night, feeding on other insects and plant matter. During the day, they can be found in crevices between or under rocks, or in other dark places. Earwigs sometimes enter homes looking for dark hiding places.

Identification

Appearance
Earwigs are reddish-brown and about 13-20mm in length. The earwig is known for its pincers, or forceps, on its posterior end, used by females to protect families against dangers. The forceps vary in length but can used to distinguish between males and females. Male forceps are curved and longer than those of females whose are straight sided. They also have long antennae made up of 15 different segments.

The forceps do bestow a daunting appearance to the earwig, and are likely the source of the completely unfounded myth that the earwig will crawl into the ear and bore into the brain. There is no documented evidence that this has ever occurred.

Indicators
Earwigs are mainly pests of seedlings or new growth such as blossoms, shoots, and soft fruits. Earwigs eat small holes toward the edges of leaves, or sometimes entire sections of new growth.

Life Cycle

Females lay about 60 round eggs, which hatch into larvae in the spring and mature in about 70 days. They live for about a year, many dying off during the winter after their birth.

Natural Enemies

Earwigs have developed a couple of natural enemies in North America since their arrival at the beginning of the 20th Century. Two fly parasites, a roundworm parasite, as well as a fungal disease are all known to kill earwigs.

Monitoring

Earwig damage is similar to the damage of other pests. They will eat small holes in plant leaves and may even kill seedlings if their populations are high enough. The best way to determine the presence of earwigs is walking through the garden at night with a flashlight and looking for actively feeding earwigs or setting out a trap and checking it daily for their presence.

Action Threshold

Earwigs are beneficial predators of many pests. In apple orchards, they are often the primary predator of aphids. They are also beneficial predators of cabbage looper pupae, webworms, and other caterpillars. Note also that earwigs do not bite humans. Control action is only recommended when damage attributed to earwigs exceeds aesthetic standards.

Physical/Mechanical Controls

Rows of plants with bare soil between often force earwigs to feed on seedling plants. Maintain a diverse soil surface of compost mulch to prevent earwigs from damaging plants.

If earwigs are getting into the home, remove individual insects by vacuuming. Caulk any cracks and openings in exterior walls.

Remove piles of organic matter near the home and cut any branches or foliage that touch the house.

Earwig traps can be made out of rolled up newspapers, sections of garden hose, or bamboo. Simply dampen the trap you plan to use and set it out in a moist, shady section of your garden. These traps mimic the type of areas earwigs like to stay in during the day. Check the trap daily and flush any found earwigs down the toilet.

Biological Controls

In the Northwest United States and British Columbia, Canada, earwig biological control programs have been undertaken using the imported parasitic fly Bigonicheta spinipennis. This predator has spread widely.

Chemical Controls

Not recommended.

References

Cloyd, Raymond. "IPM: Home, Yard, and Garden: Earwig." 2007. University of Illinois Department of Natural Resources and Environmental Sciences. 15 Aug 2008. < http://ipm.uiuc.edu/hyg/insects/earwig/index.html>.

Ellis, Tom. "Earwigs." Michigan State University Department of Entomology. 14 Oct 2008.
<http://web1.msue.msu.edu/imp/mod02/01500548.html>.

Flint, Mary Louise, and Steve H. Dreistadt. Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control. Berkeley: UC Division of Agriculture and Natural Resources and the University of California Press, 1998.

Lifton, B. Bug Busters. Garden City Park, NY: Avery Publishing Group, 1991.

Olkowski, William, Sheila Daar and Helga Olkowski. Common-Sense Pest Control: Least-Toxic Solutions for Your Home, Garden, Pets, and Community. Newtown, CT: Taunton Press, 1991.