Earwig Biology, Elimination
Earwigs, An Occasional Invader
Earwigs are beetle-like, short-winged, fast moving insects about one-half to one inch in length. They have chewing-type mouthparts, a pair of pincer-like appendages at the tip of their abdomen and are dark brown in color.
Earwigs usually hide in cracks, crevices, under bark or in similar places during the day, but are active foragers at night. They are usually scavengers in their feeding habits, but occasionally feed on plants. This information is very important to remember when killing earwigs that invade homes. For more information, go to Earwig Elimination.
The name earwig is derived from an old superstition that these insects enter human ears and work their way into the brain where they become attached and eventually drive their host to madness and/or death. This fairy tale has no foundation and is entirely false. Earwigs cause no physical harm to man. Certain species have scent glands from which they can squirt a foul-smelling liquid. This is probably used for protection; however, it makes them very unpleasant when crushed.
The striped earwig adults are dark brown with light tan markings. The males are large and robust with stout pincers. The females are somewhat smaller and lighter in color than the males. These earwigs are in areas having sandy or clay soils, and it lives in subterranean burrows or under debris. They are usually found outdoors unless populations are large or other conditions are adverse. They enter structures in search of food, a more suitable environment or just by accidental meandering.
Because of their nighttime activity, they remain in the soil or under debris during the day. Heavily thatched lawns or mulched flower beds are among their preferred daytime habitat. At night they collect in large numbers around street lights, neon lights, lighted windows or similar locations where they search for food. Favorite foods include armyworms, aphids, mites and scales. They also forage on food scraps or dead insects.
The female lays about 50 tiny eggs in a subterranean burrow. The eggs hatch into nymphs in about 7 days and the nymphs feed on their egg case. The female continues to care for the young, grooming and manipulating them in the burrow throughout the first nymphal stage. The young nymphs are about one-eighth inch long.
In about seven days, the nymphs molt into the second stage and they are released from the burrow by the female. At this time the female loses her maternal instincts and many times will devour the nymphs before they can hide. During later stages, the nymphs tend to be cannibalistic. After passing through 6 nymphal stages, the earwig becomes an adult, the life cycle egg to adult having taken an average of 56 days.
To kill earwigs, the standard bug sprays (Dursban, Diazinon, etc.) will not do; instead, use Carbamate insecticides such as Ficam W, Baygon WP or even a synthetic pyrethrin such as Cypermethrin. Control of earwigs parallels that of Centipedes, Millipedes and is considered an Occasional Invader in the pest management industry. For more about control of this group of pests, go to Centipedes, Millipedes, Occasional Invaders.