Earwig Control

By Mary Bernard, Master Gardener

Earwigs are common pests in gardens, landscapes and they occasionally invade the home. Adult earwigs are about 0.75 inch long and reddish brown with a pair of prominent forceps at the rear of the body.

Earwigs feed on other insects and are beneficial in the garden when they do so. But they can become pests when they eat valuable plant parts or are nuisances in homes. European earwigs sometimes destroy seedlings, flower blossoms, buds, and leaves. They also eat dried plant material, ripe fruit, and garbage. Other species of earwigs have been found eating dog food, stored potatoes, flour, and melons.

Since earwigs feed at night, the damage they cause may be the only evidence of their presence. Seedlings may be destroyed. Leaves and flowers may become riddled with irregular holes and notches. This damage should not be confused with that of other pests such as snails, slugs, and certain caterpillars and weevils which also feed at night. For positive evidence search until the pest is found. Many of these pests can easily be seen at work during the night with the aid of a flashlight.

At certain times of the year earwigs may become a nuisance by wandering into homes in large numbers. The striped earwig brings with it a very disagreeable odor, especially when crushed.

With extra patience, earwigs can be controlled without using insecticides by taking advantage of their natural habits. Since they crawl into dark cracks and crevices to spend the daylight hours, a rolled up newspaper becomes a convenient hiding place. Pick up the newspaper every day or two and simply crush or dispose of them of them. Sections of old garden hose, bamboo, or corrugated cardboard also make excellent hiding places. Quickest control is achieved by using numerous traps throughout the yard. The traps can be hidden beneath shrubbery and ground cover plantings, or against fences.

A sticky band of Tanglefoot around tree trunks will prevent earwigs from crawling into trees. Good garden sanitation helps to deter large infestations. Remove piles of debris where earwigs are living and breeding.

Earwigs can be controlled with baits, but these must be used with caution around children or pets that may eat it. Most baits must be kept away from direct contact with plants grown for food and should not contact any tender plant parts. Follow the label directions carefully. Do not water for 2 to 3 days after treatment.

University of California Cooperative Extension Master Gardener Volunteers can provide additional gardening information upon request .Call the San Luis Obispo office at 781-5939 on Mondays and Thursdays from 1 to 5 PM.  You may also call the Paso Robles office at 237-3100 on Wednesdays from 9 AM to 12 PM.  The San Luis Obispo Master Gardeners website is at http://groups.ucanr.org/slomg/.  Questions can be e-mailed to: mgsanluisobispo@ucdavis.edu.