Some insects are interesting, beautiful and otherwise beneficial. There are others that seem to draw universal disdain. One of these is the earwig. But is an earwig a "911 insect," one that elicits panic, fear and screams for help?
Earwigs are fairly abundant and are found in many areas around the world. There is no evidence that they transmit diseases to humans or other animals. Their pincers, otherwise known as cerci, are commonly believed to be dangerous, but in reality, even the curved pincers of males cause little or no harm to humans. It is a common myth that earwigs crawl into the human ear and lay eggs in the brain.
Male earwigs have curved "pincers" or cerci on their posterior end while female cerci are straighter, almost parallel. The only earwig in the U.S. is the European Earwig which was introduced to this country in 1907 from Europe.
There is a debate whether earwigs are harmful or beneficial to crops, as they eat both the insects eating the foliage, such as aphids, and the foliage itself, though it would take a large population to do considerable damage. Earwigs eat a wide variety of plants, and also a wide variety of foliage including the leaves and petals. They have been known to cause economic losses in fruit and vegetable crops. Most common damage observed has been chewing damage to flower petals.
Earwigs live for about a year from hatching. They start mating in the autumn, and can be found together in the autumn and winter. The male and female will live together in a chamber in debris, crevices or soil. From midwinter to early spring, the male will leave, or be driven out by the female. Afterward the female will begin to lay 20 to 80 pearly white eggs.
Earwigs are among the few non-social insect species that show maternal care. The mother will pay close attention to the needs of her eggs, such as warmth and protection. The mother will also vigorously defend the eggs from predators. Another distinct maternal care unique to earwigs is that the mother continuously cleans the eggs to protect them from fungi. The mother may assist the nymphs in hatching. Nymphs continue to live under their mother's protection until their second molt.
Earwigs are active at night so you will usually miss their feeding. They like to be in tight places. That is why when you open up an infested flower, many earwigs will come scurrying out from their hiding places. While there are other kinds of earwigs in the world that can fly, our earwig cannot, in spite of having wings.
While mainly a nuisance pest of flowers, they can sometimes enter houses. For best control you should eliminate damp, moist areas in crawl spaces or adjacent to the house foundation. This means keeping mulches away from the house. Substitute a gravel border around the foundation instead. Eliminate weedy areas and yard debris in general. If you must use an insecticide, concentrate it around the house's foundation and door thresholds. Any of the synthetic pyrethroid insecticides will work.
So is our earwig something to fear? I think not.
Jim Leser retired to Cedaredge in 2007 after a career with Texas A&M University Extension in entomology. He is a member of the Cedaredge Tree Board and a Colorado Master Gardener.