In the garden: A wide range of flowering plants such as dahlia, chrysanthemum and clematis.
On Crops: Seedlings, potted plants, basil, leafy greens, fruit trees. Occasionally will cause damage to soft and stone fruits such as strawberry, raspberry, nectarine and apricot. However, earwigs are also effective predators of aphids and other small plant pests.
Worldwide in temperate climates
Moist, dark places such as the mulch around a compost pile are the natural habitat for earwigs, which look like dark brown alligators with harmless pincers, which are used for mating. Earwigs eat mostly decaying plants and small soft-bodied insects. But when rainy weather forces them to seek dry shelter, earwigs crawl up into plants and eat leaves. Earwigs live in family groups, which often find shelter under moist flowerpots, and come out at night to eat the plants in the pots.
Plants that are being fed upon by earwigs become ragged overnight, with some leaves only partially rasped through, accompanied by a light scattering of black particles of earwig excrement. During the day, earwigs often can be found under pots or flats that contain damaged plants.
Be prepared for outbreaks in rainy years when earwigs are likely to seek above-ground shelter. Oil pit traps, described below, can be put out before earwigs become a serious problem.
Near potted plants or in the garden, the best way to trap earwigs is with an oil pit trap. Use a small plastic container with lid, and cut a pencil-size entry hole in the top. Place a shallow pool of any vegetable oil in the container with a splash of soy sauce for aroma. Replace the lid, and put the trap where earwigs are likely to be present, such as near the base of large planters or between cabbage plants. Empty and refill traps every few days.
Avoid growing susceptible plants close to hedges and walls covered in ivy as these can harbour large numbers of earwigs.