Earwigs are insects in the order Dermaptera, meaning “leather wing”. They are fearsome looking insects known for the false superstition that they will burrow in the ears of humans. While they can give you a little nip if you pick one up, they cannot burrow into people. They are generally considered harmless creatures living in mulch and organic debris on the ground. Occasionally, when conditions are favorable, earwig populations can get quite large and become temporary pests in or around homes.
Description and Behavior. Earwigs are medium-sized insects, usually brown to black in color. A few have yellow or tan stripes on their legs or bodies. Although some species are always wingless, most adults have fan-shaped wings hidden under leathery wing coverings. Immature earwigs are always wingless. Both immature and adult earwigs have curved pinchers at the end of their bodies (abdomen). They usually use their pinchers to protect themselves and their offspring from predators, but in some cases, they may use them to catch prey. Most earwigs only eat decaying plant material, pollen, or dead insects. In very high numbers, some species may damage cultivated plants, while others are considered beneficial predators of plant pests.
European earwig (Forficula auricularia).
David Cappaert, Bugwood.org
Photo displaying the earwig’s unique fan-shaped wings.
Whitney Cranshaw, Colorado State University, Bugwood.org
Types
There are 28 species of earwigs found in the United States. The European earwig is the most common species found in South Carolina and is the most common earwig pest around homes. As with many other household pests, they are often associated with moist conditions. They do not survive well in hot, dry conditions. The ring-legged earwig is found in the south as well. While this earwig is usually found outdoors, it can become a pest of moist, improperly stored grain products. Another southern species is the striped earwig. These are common in agricultural fields and gardens. They are actually beneficial, feeding on many important pests like aphids, scales, mites and other small plant insects.
Life Cycle and Habits
Earwigs mate in the spring, and the female cares for the eggs and the young for a short time after they hatch. Females can lay between 30 to 50 eggs in a batch and may produce several batches. If disturbed with her eggs, she will move them to a new location. Females can be very defensive of their nest and will protect offspring if disturbed. When the female is not guarding her eggs, she will clean them to remove fungus and mold spores. Earwigs will also “adopt” abandoned eggs and steal eggs from other nests to care for them. After the eggs hatch, the mother will continue to protect their young and bring them food for a couple of days. The wingless young take between two to three months to become adults. Adults may live up to seven months.
Earwigs are active at night and will remain hidden under protective surfaces and in cracks. They often prefer to live under mulch, boards, rocks, woodpiles and other cool, damp places. If they are living indoors, they are usually associated with plants that have been brought inside from outdoors. They may also be found in areas with moisture problems around doors, windows and garages. Sometimes, they nest under carpets that remain wet.
Nonchemical Control
Since earwigs are attracted to moist organic areas, one of the best nonchemical control strategies is to maintain dryer conditions. Correct any indoor moisture problems, reduce excessive mulch, and cut back on watering near the house if earwigs become a problem. Moving woodpiles, stepping stones, wet outdoor mats, and debris away from the foundation of the home will reduce population outbreaks.
Often, when earwigs are found in a home, they are few in number. Hand removal or vacuuming is all that is needed in this case. Make sure you caulk or apply weather stripping around doors, windows, and other points where earwigs may be entering the house.
Chemical Control
If earwig populations are large or persistent, outdoor chemical treatment may be needed. Usually, outdoor treatment coupled with indoor hand removal will eliminate the problem. Insecticide dusts lightly puffed into voids and spaces around doors and walls that you cannot effectively caulk will at least kill earwigs as they try to enter your home. In mulched areas, consider using insecticide granules or liquid sprays. Buy products that are listed for the areas you want to treat and have earwigs on the label. Make sure you get the granules or spray down into the mulch or leaf litter to reach where earwigs like to live and feed. Remember that insecticide treatments will only provide temporary control. Removing, reducing or drying the places earwigs like to live will provide the best long-term control.
Sources used in update:
- Boos, S., J. Meunier, S. Pichon and M. Kölliker. 2014. Maternal care provides antifungal protection to eggs in the European earwig. Behavioural Ecology 25: 754–761.
- Welcome to the Earwig Research Centre (earwigs-online.de)
- Butnariu, A.R., Pasini, A., Reis, F.S. et al. Maternal Care by the Earwig Doru lineare Eschs. (Dermaptera: Forficulidae). J Insect Behav 26, 667–678 (2013). https://doi.org/10.1007/s10905-013-9377-5
Originally published 06/03
