One of the more ominous-looking garden insects is the earwig. About 1/2-inch long with a flattened brown body that reminds you of a cockroach, this insect has fearsome-looking but harmless pincher forceps and two pairs of wings. You often find them roiling about in moist garden mulch or beneath logs and other debris.
As bad as earwigs look, they are not very serious as garden pests—and sometimes are more friend than foe. It's true that common earwigs (Forficula auricularia) can feed on tender shoots and can occasionally make a holy mess of leaves and even flowers, but the amount of damage they cause shouldn’t present a major problem in most gardens. The repulsion some people feel about earwigs is more about their appearance than their behavior.
In their favor, earwigs eat aphids, snails, slugs, and some types of insect larvae, so you might actually want them around. However, as with all uninvited creatures in a garden, there are times when earwigs can be considered a pest. When that happens, be patient and learn why earwigs are attracted to your garden. Controlling them is often just a matter of adjusting the environment.
5 Ways to Get Rid of Earwigs in the Garden
Dry Out the Garden
The first strategy to try—and often the only one necessary—is to clear the ground mulch from the area where they are congregating and to let the soil get a bit dry. You only have to do this temporarily, until the earwigs move on. Then you can replace the mulch to enjoy the benefits it brings to garden soil. Removing the mulch may also have the benefit of reducing slugs, snails, and similar pests, since they, too, thrive in moist debris covering the garden floor.
Use Homemade Traps
Place damp, rolled-up newspapers or small cardboard boxes (such as a cereal box) in the garden area in the evening. Earwigs feed at night and look for a damp, sheltered spot to spend the day. You can pick up quite a few in the newspaper the next morning. The Cooperative Extension System recommends baiting these traps with oatmeal or bran if you are having trouble attracting them into these homemade traps.
Another method is to set out traps made with shallow cat food or tuna cans filled with a thin layer of vegetable oil. The insects will be attracted to the oil as a food source and you may be able to eliminate a large number on a daily basis.
Apply Sticky Barriers
Apply a sticky barrier, such as Tanglefoot, sticky tape, or even petroleum jelly at the base of woody plants. Earwigs are crawlers and will get stuck in the sticky mess before they can get up the tree or shrub to cause damage.
Apply Diatomaceous Earth
Apply diatomaceous earth (DE) to the soil to deter earwigs; reapply in one week, if necessary. Diatomaceous earth is a natural mineral that contains the powdered remnants of fossilized diatoms, a type of hard-shelled algae. DE works as a pesticide because the sharp powder penetrates the shell or skin of creatures such as earwigs, slugs, and snails, causing them to lose body moisture. It is a natural, non-chemical means of pest control that is preferred by organic gardeners.
As a last resort, outdoor insecticides labeled for crawling insects can be used, such as Diazinon. Follow the manufacturer's direction carefully. Typically, it's best to apply treatments in the evening, before feeding begins.
What Causes Earwigs in the Garden
Earwigs like damp, sheltered places, including mulched garden beds or areas under potted plants. These conditions, along with a supply of food, will tempt earwigs into your garden. However, since they are considered beneficial insects, they are only treated as pests when their damage becomes excessive.
Earwigs commonly eat plant debris they find on a garden floor and under containers. They may also feed on a wide range of garden plants and seem to be especially fond of herbs and corn tassels as well as dahlias, marigolds, roses, and zinnias. They can also be a pest of fruits such as berries, apricots, and peaches. Unfortunately, if none of their favorites are available, earwigs may feed on whatever plants they can find.
But earwigs are often considered beneficial insects and are sometimes deliberately introduced to control aphids and other damaging insects. Seeing only a few is more a cause for celebration than for panic. Garden earwigs require control only when the plant damage they do outweighs their benefits.
Do Earwigs Bite?
Earwigs do not feed on blood or bite in a traditional way, but they may pinch as a defensive move if you pick one up by hand. This almost never pierces the skin, though you may feel the pinch and sometimes it can even leave a small bruise.
How Long Do Earwigs Live?
Earwigs live about one year from hatching. Mating occurs in the fall, at which time you can find the males and females living together in ground debris, in crevices, or in the soil. Eggs are laid in late winter or early spring, which hatch in about seven days into nymphs that are smaller versions of adult insects. Through a series of molts, the nymphs gradually transform into adults, which will mate in the fall. The previous generation typically dies out sometime during the growth of the nymphs into adults. Warm climates may see two generations of garden earwigs each year.
Because cold weather kills off most earwigs, relatively few mating couples survive the winter to reproduce. Thus, this is not an insect that is usually found in large numbers in cooler climates.
Do Earwigs Carry Diseases
Even if earwigs did carry disease, they wouldn't cause much of a problem since they virtually never bite, nor do they transmit pathogens to foods eaten by humans. They can, however, potentially transmit fungal or bacterial plant diseases around the garden, though such transmission is far more likely with other insects that feed primarily on living plants.
Are Earwigs Found Indoors?
There are many species of Forficula falling under the common name "earwig," and some of them are relatively common pantry pests. However, the common (or European) earwig (F. auricularia) is primarily an outdoor insect that is only occasionally found indoors. When you find them indoors, it is usually in dark, moist areas, such as beneath piles of newspaper or cardboard boxes. They may also hitchhike in on potted houseplants that spend the summer outdoors. But the common earwig does not deliberately seek out indoor environments to feed or overwinter. If you notice such insects indoors in substantial numbers, it more likely a different, similar-looking species of earwig.
Where Does the Name "Earwig" Come From?
The common name derives from the Greek words ēare, which means "ear," and wicga, which means "beetle." There are various theories about the origin of this name. Some entomologists believe it derives from the fact that the hind wings resemble a human ear when they are unfolded. A more widely accepted view is that it derives from an old wive's tale that told of earwigs boring into human brains through the ear canal to lay eggs—the source of a number of plot lines in horror and sci-fi movies. This may have been more a cautionary tale aimed at coaxing children into better hygiene, as there is virtually no legitimate evidence of such a thing—though it's not unheard of for insects to accidentally wind up in a human ear.