Earwigs
The European earwig was not known to occur in the
United States prior to 1900. They are a native of Europe,
western Asia and northern Africa and have been introduced
into East Africa, the East Indies, Australia, New Zealand
and North America. In North America it was first reported
from both the Pacific northwest and Rhode Island and
eastern Massachusetts. It now occurs throughout most of
the northeastern states and the west coast north of
central California, with localized infestations in Utah
and Colorado. The European earwig has been found in
Michigan since the mid-1960's.
Earwigs have benefited from man's activities. As a
result, the density of earwig infestations is closely
related to the level of human activity. Earwigs rarely
fly and they are unable to crawl for long distances, yet
they have spread rapidly through the eastern and western
United States. This is because they are accomplished
"hitch-hikers". They wander about at night and crawl into
any available hiding place before dawn. Thus they may be
carried long distances in bundled newspapers, luggage,
cut flowers and produce, crated merchandise, lumber and
building supplies, automobiles and even the mail.
The European earwig is a medium-sized insect (1/4 to
1 1/4 inch) that is easily recognized by the reddish-
brown color, short wings, and prominent forcep-like
appendages at the tip of the abdomen. The native
ringlegged earwig, Euborellia anulipes (Lucas), may also
occur around buildings in Michigan. The species can be
distinguished by the shape of the forceps.
The name "earwig" originated in Europe and is based
upon a popular, but totally unfounded, superstition that
earwigs enter the ears of sleeping persons and bore into
the brain.
Earwigs develop from eggs to adult via gradual
metamorphosis and the rate of development is temperature
dependent. The earwigs overwinter as pairs in cells in
the soil. The males are evicted from these cells in the
early spring as the female prepares to raise the first of
two broods. Each female lays 20 to 50 small, white eggs,
and she protects them from natural enemies, desiccation
and mold.
The early spring brood requires an average of 70 days
for incubation; the second, late spring brood only
requires an average of 20 days for incubation.
The immature earwigs (nymphs) resemble the adults
except for the smaller size, grayish-brown color and lack
of wings. They require an average of 50 days to reach
maturity.
Earwigs are omnivorous. They will consume algae,
fungi, mosses, pollen, insects, spiders and mites (dead
or alive). The plant material almost always constitutes
the bulk of the diet. Thus, earwigs may damage flowers,
vegetables, fruits, foliage of ornamental trees and
shrubs, and even honey in bee hives. Fortunately, the
damage by earwigs is generally much less severe than
would be expected by the actual concentration of earwigs
present.
Earwigs are first-rate nuisance pests. They are found
in and around homes and may be found in household
articles, foodstuffs, crawl spaces, debris, cut flowers,
produce and shrubbery. Their grotesque appearance,
secretive habits and occasional foul odor are the primary
reasons for homeowner disdain.
Earwigs can be controlled through a variety of means,
including natural enemies, trapping, and insecticides.
When the European earwig was introduced into the United
States it had no natural enemies. Today we benefit from
the activity of several natural enemies, including two
fly parasites, a roundworm parasite and a fungal disease.
To fully benefit from these natural enemies it is best to
avoid using insecticides during the early summer when the
adult parasites are active.
Before attempting other types of control, be sure to
remove all debris (boards, stones, paper, etc.) and use
mortar or caulking compound to seal all cracks and
crevices in the outside of the house. Since earwigs are
attracted to light it may be necessary to reduce lighting
around doors, or to use non-attractive (yellow) bulbs.
Earwigs can be easily trapped and destroyed. Set out
rolls of newspaper in shrubbery, mulch, tree crotches and
similar areas. Burn or destroy the rolls daily. Or, try a
box trap. To make the trap use a pencil to punch holes in
the side of a cardboard box near the bottom. Bait the box
with oatmeal or bran and set them out in infested areas.
A third alternative is to set out pieces of heavy burlap,
canvas or newspaper. Each morning pick up the burlap and
quickly spray with one of the suggested out door
insecticides.
If you choose to use an insecticide out of doors, a
diazinon 25% EC formulation sprayed completely around the
outside foundation is suggested. If you choose to use an
insecticide indoors a ready to use spray of chlorpyrifos,
or propoxur is suggested.
For a complete listing of suggested control options
for all home, yard and garden insect pests see: Michigan
Insect Pest Management Guide, 1991. This publication is
available from the Cooperative Extension Service.
Read and follow instructions on the pesticide label.
Heed all warnings. Check with your physician if you have
any concerns regarding your personal health risk.
Revised by Tom Ellis, M.S., Department of Entomology
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This file was generated from data base 02 on 05/28/97.
Data base 02 was last revised on 10/01/92.
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