Project Description

Earwigs

Earwigs are one of the most disliked insects. The European earwig is the most common species. It can be found outside and inside the home. They enter a house with the help of a host – on humans, clothing, vegetables, newspapers, etc. Earwigs are reddish-brown, approximately 4/5 of an inch (2 cm) long with antennae and a noticeable set of pincers which protrude from the abdomen. The pincers of the male are curved whereas those of the female are straight. The female uses her pincers to protect herself and eggs from other insects, but they cannot harm humans. Earwigs have wings but they are rarely used to fly. Earwigs wait for darkness to begin their search for food and shelter. They enjoy dark, moist areas and feed on decaying plant and animal matter. They also cause slug-like damage to leaves, petals, fruit and vegetables. One way to determine if a slug or earwig is the cause of damage is to look for a slimy substance which slugs leave behind. Earwigs also damage vegetables by entering and enlarging existing holes.

Earwigs can be beneficial in the garden if they can be prevented from damaging vegetables and flowers, and entering the household. It is important to avoid killing earwigs because they are predators of some small insect pests such as aphids.

Life Cycle

The life cycle of the earwig consists of egg, nymph and adult. In early spring, after overwintering in soil, the female earwig lays up to 60 eggs in the top section of soil. In about seven days, the eggs hatch and nymphs emerge. The female tends to the eggs and nymphs for the first two weeks. The nymphs are similar to adults, only smaller. Over a 70 day period, the nymphs pass through four growth stages before becoming an adult. Egg laying can take place twice per year (spring and summer). Adult earwigs will be most noticeable in July, August and September. Earwigs live for approximately one year, but most often the males die during the winter months.

Physical Control

If earwigs are damaging your plants, there are some physical control measures available. Since they are active at night, check your garden with a flashlight to determine if earwigs are present and causing damage. Practice sanitary conditions around your home by removing leaf litter, stacks of firewood, decaying matter and other items which attract earwigs.

Earwig traps are easy to construct and very economical. Take a rolled up newspaper, a piece of corrugated cardboard or a paper towel tube filled with straws and seal it on one end. Place it in an area of the garden where earwigs have been observed. When the earwigs crawl inside, it is next to impossible for them to escape. A bait of honey or peanut butter can be used to attract earwigs to these traps, but it is not necessary. Another trapping method is to place a shallow dish or can in a hole so that the top of it is at ground level. If a tin can is used, an empty tuna or sardine can with oil remaining on the inside is best. In the morning, check the traps and shake all captured earwigs into a bucket of soapy water.

To limit the number of earwigs which find a way into the household, take time to shake and look at objects before bringing them inside, seal cracks and check window openings and doors. Also check damp hiding places such as windows, flooring and under sinks. Earwigs may be found indoors during hot, dry summers.