Earwigs are a fairly well known insect, from folklore if not from actual experience. The earwig is the insect reputed in superstition to purposefully crawl into the ears of sleeping persons, and from there bore into the brain. Of course, there is no truth to these tales.
Earwigs are fairly common, though not often abundant in Iowa. They are rarely noticed except after prolonged periods of a year or more with wet weather.
Earwigs are relatively easy to identify by the prominent pincers or forceps on the end of the abdomen. On females the pincers are fairly straight, while male pincers are more curved and caliper-like. These pincers are used as both offensive and defensive weapons. Though they may try to pinch if captured and handled, they do not harm people. The common earwig is about 5/8 inch long and dark brown with a reddish head and pale yellow-brown legs.
Earwigs are outdoor insects that are usually found in damp areas, such as under mulch, dead leaves, logs, and piles of firewood, boards, stones and other debris or in rotted wood where they feed on moist, decaying plant material. Though earwigs occasionally attack living plants, including vegetables, fruit trees and ornamental plants, they are considered only minor pests of plants because damage is widely scattered.
Like boxelder bugs, crickets and elm leaf beetles, the earwig is a pest as an accidental invader. They enter houses either by accident or when seeking shelter, especially in the fall. Earwigs inside the house do not cause any harm or destruction. They are merely an annoyance or nuisance because of their presence. If disturbed, earwigs may produce a noticeable foul odor.
Control of earwigs is generally not necessary in Iowa. Barrier treatments around the house and on the foundation could be used if large numbers of earwigs are present. However, this treatment is neither practical nor efficient if only a few earwigs are present. Earwigs found inside the house need only be swept or picked up and discarded. Indoor treatment as for cockroaches could be used, but again will almost never be necessary or warranted.
This article originally appeared in the July 11, 1997 issue, p. 111.