Gardening: Earwigs mostly helpful (don’t worry about your ears)

I am hearing rumors that earwigs have invaded gardens in the area. Take a deep breath: They are more of an annoyance than a destructive pest.

Earwigs, like a lot of our insect pests, are native to Europe and hitchhiked here on plants around 1900. There they were the subject of folklore that said they would crawl in the human ear and lay eggs. The larvae were said to then bore into the brain. There is no truth to this myth. Earwigs don’t go looking for ears to crawl in although they, like a lot of other bugs, might accidentally find their way there but only rarely.

The insect is about 5/8 inch long with a flat, reddish brown body and short wings. They have medium length antennae and chewing mouthparts. Their most distinctive characteristic is a pair of strong pinchers on the end of their abdomen, which they use to protect themselves and to grab and hold prey. Males have stout, strongly curved pinchers widely separated at the base while females possess slender, straight pinchers that are close together. Juvenile earwigs called nymphs look like a small adult with femalelike pinchers and are usually lighter in color than adults. Earwigs can use their pinchers to attach to a finger but it is purely a defensive move; they have no venom or stinger.

In general, earwigs are beneficial scavengers in the garden. They feed on rotting and damaged vegetation and hapless dead and dying insects. However, they also feed on desirable vegetation like marigolds, dahlias, butterfly bush, hostas, corn silk and seedlings. They usually chew irregular holes in leaves and flower blossoms that can resemble slug damage. Large plants can usually withstand damage but smaller ones can be killed if there is a large population.

The insects are nocturnal – they feed at night and seek out cool, dark, damp places during the day. Males and females mate in the fall and share a ground nest until late winter when the male is forced out. The female lays her eggs, which hatch in about a week. The nymphs emerge in late May to early June and mature into adults in late June to early July. The adults remain active into the fall.

The best way to control them is to trap them where they hide. Because they hide under damp mulch and garden debris during the day, remove debris and thin mulch to reduce their habitat. Allow the mulch to dry out between deep waterings. Lay out rolled up newspaper, pieces of plastic pipe and tuna fish cans filled with fish or cooking oil around favored plants. In the morning, shake the traps into soapy water and reset them.

If the infestation is significant, residual insecticide baits containing carbaryl or sprays of permethrin, deltamethrin or acetamiprids can be applied. These insecticides can be found in many commercial products. Always read and follow the label instruction when applying so that you minimize damage to beneficial insects you want to keep around.