How can I control earwigs in my home and garden?
The earwig got its name from an old superstition that it could crawl into peoples’ ears while they sleep and bore into the brain. This belief is not true. Earwigs can, however, chew into plants and cause damage and can be a nuisance around the home. Consider this information for control.
The most common type of earwig found in home yards in Utah is an exotic species called the European earwig. Earwigs are easy to recognize from their cerci, the large, pincer-like appendages on the hind end. Cerci are used in self-defense and courtship and will deliver only a mild pinch to humans. The earwig body is flat and elongated and red-brown in color. Earwigs are one-fourth to one and one-fourth inches in length. Adults have a short pair of leathery wings covering a folded pair of membranous wings. They are weak fliers and move mostly by crawling. Earwigs can emit a foul smelling, yellow-brown liquid from their scent glands. They are omnivorous and will scavenge on dead insects and decayed organic matter, prey on live insects and chew on living plant material including leaves, flowers, stems, fruits and roots.
Earwigs are pests outside the home because of the damage they can cause to ornamental and garden plants, and a nuisance when they enter homes seeking shelter and food. If damage to garden plants is apparent or many earwigs enter the home, control measures should be considered. Garden plants commonly injured by earwigs in Utah include annual flowers (especially marigolds, dahlias and zinnias), herbs (especially basil), roses, raspberries, strawberries, apricots, peaches, sweet corn tassels and silks. Because earwigs are beneficial due to their predaceous and decomposer feeding habits, they should only be controlled when causing harm. Earwigs are nocturnal. If chewing injury to plants is apparent but no culprit can be found during the day, check the plants at night with a flashlight. If shiny, slime trails are present, snails or slugs are the culprit rather than earwigs.
For earwig control, focus on the outside of the home where populations increase during spring and summer. To reduce their entry into your home, create a clean, dry border using gravel or stone immediately around the foundation wall. Eliminate hiding places near the foundation such as groundcovers, climbing vines, weeds, thick mulches and vegetation and piles of debris, leaves or wood. Earwigs hide under mulches in plant beds during the day, so be sure to select mulches with smaller-sized particles to reduce refuges. Seal cracks and crevices around windows, doors and cable holes in walls. Apply insecticides (see recommended products below) around the foundation, flowerbeds and turf within several yards of the home. In late spring to early summer, suppress earwig populations by targeting sites where they congregate (sites where females brood their young), and on plants when injury appears. Place traps in the evening and collect and remove earwigs in the morning. Effective traps include shallow cans with vegetable or other odorous oils, moist rolled newspaper and cardboard boxes baited with oatmeal or bran. Be sure cardboard containers have pencil-sized holes near the bottom for entry.
Apply an effective insecticide in the late evening just before earwigs come out to feed. Recommended insecticides include permethrin, esfenvalerate, bifenthrin, pyrethrins, carbaryl, malathion, azadirachtin and diatomaceous earth. Use enough water in the application to cover plants and carry the chemical into the top layer of soil or mulch where earwigs hide. Not all insecticide products are registered for edible plants. Read the product label carefully before making an application.
Posted on 22 Jul 2005