L-1834

Earwigs are abundant in Texas and are a nuisance when they invade homes. They are rarely harmful to man, but have large, pincher-like abdominal appendages called forceps, which present a formidable appearance. Earwigs have flattened bodies and can enter homes through very small cracks. However, they are accidental invaders and do not reproduce indoors.

A few earwig species cause some damage by feeding on crops and ornamental plants but most play a beneficial role by feeding on other insects. Some species emit a foul odor. However, the most common complaint against the earwig is its mere presence in homes and apartments. Its name comes from a European superstition that the insect would enter the ear of a sleeping person and bore into the brain.

Biology and Description

Earwigs are medium-sized insects ranging from 5 to 31 mm (1/4 to 1-1/4 inches) in length. They are flattened from top to bottom, which allows them to crawl through extremely small cracks. Their color ranges from brown to black and some species have yellow or buff-colored stripes or a reddish coloring on the head and body. All earwigs have a pair of hardened abdominal appendages which protrude backwards as a tail. These appendages vary between species and from male to female. Adult earwigs also have a short, leathery pair of wings. A second pair of membranous wings may be folded underneath the first pair. Because of this, the adults are sometimes confused with short-winged beetles, particularly rove beetles. However, the appendages of rove beetles are segmented, shorter and much softer.

Earwigs have chewing mouth parts which they use to catch and eat insects. They feed on both dead and living insects as well as on mosses, lichens, algae, fungi and occasionally some growing plants. Indoors, their food consists of house plants or sweet, oily or greasy foods.

Earwigs develop with a gradual metamorphosis from egg to nymph to adult. The immature forms look much like the adult but lack the wings and the large sized forceps. Females lay from 20 to 300 eggs, usually in a chamber in the soil. The female guards the eggs and the newly-hatched young. One to two generations are born each year.

At night, these insects forage for food and seek new shelter areas. They are attracted to lights and are sometimes found in great numbers under a strong light.

Earwigs prefer high moisture and migrate indoors during periods of prolonged heat and drought to seek cool, moist hiding places. During the winter they can dig into the ground as deep as 6 feet to escape freezing temperatures.

Approximately 20 species of earwigs live in the United States. About 10 occur in Texas although only three or four are a common problem in homes. They are the ringlegged earwig, Euborellia annulipes (Lucas); the riparian earwig, Labidura riparia (Pallas); the linear earwig, Doru lineare (Eschscholtz); and the brown-winged earwig, Vostox brunneipennis (Serville). These earwigs usually live along rivers, lakes and the coast.

Control

The following preventative measures help control earwigs. Eliminate any accumulations of moisture, Also, eliminate damp conditions in crawl spaces under homes, around outside faucets, air conditioning units and other places. Reduce lawn and flower bed watering wherever possible. Remove or alter places that attract earwigs such as flower gardens and sheltered areas under trash and compost or wood piles. Keep grass and weeds cut short around structural foundations. Also reduce outside lights at night, since these tend to attract earwigs.

These insects gain access indoors through very small cracks and crevices. Use caulking and weatherstripping around doors, windows, pipes and other places to exclude them. Earwigs generally enter the home at the ground level, so pay particular attention to low areas.

Use insecticides outdoors around foundations, in flower beds and under subfloor crawl spaces to limit earwig entry into structures. Apply insecticides in the late afternoon during late spring and summer. This will stop the earwigs when they are young. Sprays and granules are effective, but should be washed into the, soil with sufficient amounts of water, as earwigs can move a considerable distance into the ground. Table 1 contains a listing of insecticides registered for earwig control.

Indoor applications have limited value, since earwig populations do not establish inside. Use such treatments for spot applications to baseboards, behind draperies, carpet edges, in cabinets, door and window frames and other hiding places. Occasional bait applications may help alleviate the problem.

Insecticide label clearances are subject to change and changes may have occurred since this publication was printed. The pesticide USER is responsible for the effects of pesticides on his own plants or household goods as well as problems caused by drift from his property to other properties or plants. Always read and follow carefully the instructions on the container label.

The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied.

Educational programs conducted by the Texas Agricultural Extension Service are open to all people without regard to race, color, sex, disability, religion, age or national origin.

Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and June 30, 1914, in cooperation with the United States Department of Agriculture. Zerle L. Carpenter, Director, Texas Agricultural Extension Service, The Texas A&M University System.

20M--1-81

Return to top of page

Return to Departmental Home Page

Last modified: January 23, 1997 by Edgar Cross