Blackwelder column: Earwigs! Eeeuw – how to treat the pesky pests

Published 12:00 am Friday, May 29, 2009

Earwigs, the unwanted spring pest, usually arrive in June but have surfaced much earlier again this spring. Weather extremes, especially wet weather, seem to make these insects more prevalent as they invade all areas around the home.
Earwigs are elongated, flattened insects that may be light red-brown to black in color. They are easily recognized by their forcep-like appendages and chewing mouthparts. They also have long, slender antennae and may have wings.
Adults, along with their eggs, overwinter in the soil below the frostline to escape the cold temperatures.
Earwigs rarely fly and are unable to crawl long distances, but they have a knack for getting indoors via laundry baskets, cut flowers, luggage, newspapers, cardboard boxes, lumber, baskets of fruits and vegetables.
These insects require moist, cool places and are usually found in damp crawl spaces or basements, flower gardens near the home, in mulches, compost piles and trash, under boards and in wood piles.
During dry, hot weather, earwigs migrate indoors. They are active primarily at night and are often found around lights.
Earwigs feed on mosses, lichens, algae, fungi, insects, spiders and mites, both dead and alive.
Some earwigs are predators, feeding on aphids, while others feed on living plants and may become pests in greenhouses and on certain crops such as vegetables, fruits, ornamentals, forages and field plants.
Earwigs are easily killed by residual insecticide treatments in cracks and crevices, along baseboards, beneath cabinets, along door and window sills and other hiding places during the day. Unfortunately, control will be short-term due to new earwig entry from outdoors.
Earwigs are attracted to moisture around home during hot weather. High populations around foundations, in landscaped yards, in mulch and under boards are common.
Eliminate damp conditions in crawl spaces under houses, around exterior water spigots, air-conditioning units and along house foundations. Rain gutters and spouts should carry water away from the house foundation.
Try to concentrate insecticidal sprays on cracks and crevices where earwigs tend to hide. Any indoor treatments should supplement pesticide applications outdoors since earwigs do not typically become established indoors, other than in areas of high moisture. Insecticidal dusts and residual sprays are effective when applied to baseboards, beneath cabinets and other hiding places at the floor level.
Treat outdoors with insect sprays 18-24 inches on the foundation wall and a 3-to 6-foot band around the building to stop or limit earwigs from getting indoors. There are also indoor granular baits designed to kill earwigs, crickets and cockroaches. Granular baits contain a food attractant and an insecticide. If you plan to use the baits, do not treat these same areas with regular insecticides. Always read the pesticide label and follow directions and safety precautions.
Darrell Blackwelder is an agricultural agent in charge of horticulture with the N.C. Cooperative Extension Service in Rowan County. For archived garden columns or other information, visit the Rowan County Master Gardener web site at www.rowanmastergardener.com, or call 704-216-8970.