Earwigs are fearsome looking insects, known for the popular 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 they can become temporary pests in or around homes.
Description and Behavior. Earwigs are medium-sized insects usually brown to black in color. A few have stripes on their legs or bodies. The adults have small wings and all earwigs, young and adults, have curved pinchers at the end of their bodies (abdomen). They usually use their pinchers to protect themselves from predators, but in some cases, they may use them to catch prey. Most earwigs only eat decaying plant material or dead insects. In very high numbers, they can sometimes damage cultivated plants.
There are 22 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.
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 often pick them up as though she is cleaning them. After the eggs hatch, the 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 around moisture problems around doors, windows and garages. Sometimes they nest under carpets that remain wet.
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 problem conditions away from the foundation of a home such as woodpiles, stepping stones, wet outdoor mats and debris 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 and other points earwigs may be entering the house.
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.