

The earwig is a curious-looking insect that sometimes invades

homes. Although the earwig may look dangerous, it isn't. The common

name, earwig, comes from an old European superstition that the

insect could enter the ear of sleeping people and bore into their

brains. They cannot. Earwigs are merely annoyance pests. They do

not cause harm nor can they reproduce inside the house.



Biology and description



Adult earwigs are 1/2 to 1 inch long, reddish-brown in color, and

bear pincer-like forceps called cerci at the posterior end. Earwigs

are flat in appearance and have long legs and antennae. The

forceps-like cerci is their most obvious characteristic. Males have

strongly curved forceps; female cerci are nearly straight. Even

immatures have the forceps. Their cerci lack muscles, so although

they will attempt to grasp your finger if you get too close,

earwigs cannot do much more than hold on or give a slight pinch.



Adult earwigs have wings but do not use them to fly. Under

favorable conditions, adult females produce eggs that hatch in as

few as 12 days. Immatures that hatch from the egg look like

miniature adults, except they lack wings. But even adult earwig

wings are small, well concealed, and not evident unless the

specimen is examined carefully.



In Delaware only one earwig generation is produced each year.

Immatures appear in April or May. Adult earwigs are present from

late June to early July; with cooler weather in the fall they

burrow into the soil. Earwigs undergo gradual metamorphosis. The

female guards her white, spherical-shaped clutch of eggs after she

lays them in a protected depression in the soil. Egg clutches

number from 20 to 300 eggs.



Earwigs can enter homes or buildings through the tiniest of cracks.

Adults tend to aggregate at sites. Homeowners may suddenly discover

a population in their basement, garage, or other structure.



Earwigs prefer high-moisture conditions. They will migrate indoors

during periods of prolonged heat or drought to seek cool, moist

hiding places. During the winter, they burrow into the ground or

seek shelter deep in leaf litter or beneath structures on the

ground. They forage at night, and sometimes large congregations of

earwigs can be seen under a strong light.



Earwigs have chewing mouthparts. Scavengers, they feed on both

living and dead insects as well as on mosses, lichens, and algae.

Occasionally they feed on growing plants and may cause damage to

EARWIGS
house plants or greenhouse plant material. Inside the home they may
also feed on sweet, oily, or greasy foods. Earwigs can be found
around paper and fiber products in kitchens and bathrooms as well.

Control

Sanitation and removal of hiding places help control earwig
infestations inside. Look for earwigs around door jams, door mats,
basement window wells, beneath materials in basements or sheds,
among mulch near homes, and in kitchens and bathrooms. Earwigs are
not structural pests and do no harm with their feeding. They are
merely an annoyance. Removing the areas where they accumulate is
the best control.

Inside the house, use an indoor aerosol spray to eliminate an
earwig population. This action is not effective by itself; it works
only when hiding places are also removed. Occasional earwigs found
in sinks or inside the home can be picked up with a tissue
and-discarded outside.

If an earwig infestation is a continual problem, close cracks in
the house and foundation where they can gain entry. A residual
spray containing Sevin, diazinon, or other suitable insecticides on
the outside foundation and in window wells may help provide control
but not eliminate earwigs. For best results, clean up areas where
they hide, eliminate moisture conditions, and exclude their entry.

Dewey M. Caron
Extension Entomology
7/94
.
