While I can tolerate spiders inside my house, other crawly creatures are not welcome — and I am willing to bet that you are not cordial to them either.
This past week I have found several earwigs inside my house. I detest these fast-moving repulsive little beasts.
The European earwig is a non-native insect that is believed to have arrived in the Pacific Northwest and other parts of the country in the early 1900s and is now found throughout the country. Interestingly, there are 21 other species of earwigs found in the U.S., 10 of which are native here. However, it is the European earwig that is most commonly encountered in local gardens and occasionally indoors.
European earwigs are a dark reddish-brown color and about half an inch long when mature, but the younger nymphs are smaller and lighter brown in color. Their most distinguishing features are their elongated flattened body and the nasty looking pincers or forceps at the end of the male’s abdomen.
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As nocturnal insects, earwigs forage for food at night. During the day they hide in confined dark spaces, such as under flower pots or garden debris, inside rolled leaves or flower buds, and beneath mulches.
Earwigs are scavengers that feed primarily on dead insects and rotting organic matter, but they also nibble away on the soft tissues of some plants. They have been known to chow down on flower petals, lettuce and young tender plant leaves. They leave behind irregular holes and ragged edges. European earwigs also create holes or shallow pits on the surface of the fruit of some crops, such as strawberries, raspberries, peaches and apricots.
Despite the possible damage they do to plants, many entomologists avow that earwigs are beneficial insects. This is because earwigs are omnivores and also feed on aphids, insect eggs, maggots and plant mites. Most years, earwigs are not a serious problem and cause only minimal damage to plants. However, some years their populations explode and they become pests.
When you find an earwig or two indoors during the summer, their presence is usually incidental. Earwigs prefer cool, moist conditions and sometimes migrate indoors when summer weather turns hot and dry. In search of moisture, they are most often found in bathrooms, basements and under damp clothing. When an occasional earwig is encountered indoors, it should simply be squashed or vacuumed up.
If you experience an overwhelming earwig invasion, experts recommend eliminating habitat around the home that may be favoring their presence. This includes pulling organic mulch three feet away from the home’s foundation, cleaning plant debris out of gutters and foundation wells, trimming back plants touching and shading exterior walls, and removing any wood piles situated close to the home. Block possible entry sites into the house using caulking, weather stripping and screening.
If numerous earwigs are present indoors over a prolonged period of time, it is important to look for and correct any possible moisture situations in crawl spaces and around plumbing.
In the garden, earwig damage is usually minimal, but large populations may warrant control measures. To learn more about using non-chemical traps to control earwigs, go to bit.ly/2v1pCBl. Organic and inorganic insect baits also are available to home gardeners for control of earwigs in food gardens. These are applied to the soil at the base of plants according to label directions. Always read and follow the label directions.
Marianne C. Ophardt is a retired horticulturist for Washington State University Benton County Extension.