Walk Softly – Earwigs

by Geoffrey Carpentier

I woke up early today and went outside to watch the sunrise. A flash of colour caught my eye. Was that an earwig scurrying away across the deck?

This skinny, long-bodied insect is repulsive to most, as it seems to represent something evil and scary, due to the significant pincers at its tail end. The ‘ear’ part of the name is derived from the fact, the hind-wings of these insects resemble a human ear when unfolded. The ‘wig’ part comes from the Old English word ‘wicga,’ for insect. One myth persists which is, earwigs will crawl into your ears to lay eggs, not true!

The earwigs are part of a group of insects known as Dermaptera, represented by approximately 1900 species, in 12 families, worldwide. All are closely related, and all have a vestigial pair of wings (i.e., seemingly useless appendages with no apparent purpose, although at one time, it's thought, they would have assisted flight) and a functional pair of wings. Each species also sports two pincer-type appendages, at the end of the abdomen, called ‘cerci.’ Within this larger group of Dermaptera insects, about 1200 species of earwigs occur worldwide, with 18 species calling North America home.

Mating occurs in the autumn, when the male and female stay together for most of the autumn and winter, until she eventually drives him away after mating. Although very few parasitic species of earwigs produce live young, most will lay 20-80 eggs, over a two-day period in the spring. Uncommon in lower, non-social animals, earwigs offer a discernible level of care for their eggs and young offspring. Eventually, she can recognize her eggs by smell and will only look after them, keeping them clean, fungus free and safe from predators, until they hatch in about a week. Once they do, the young insects emerge and begin to change, through a process called incomplete metamorphosis. This is a three-step process to maturity.

Some other groups of insects (i.e., butterflies) go through four stages, starting as an egg, changing to a larva (caterpillar), then pupating and finally becoming an adult – this is called complete metamorphosis.

The earwig skips the pupal stage and goes straight from the immature form (nymphs), slowly shedding its skin five or six times until maturing into adulthood.

As their development commences, their first meal is their own egg casing, followed by regurgitated food provided by the mother. Interestingly, when they shed their ‘skin,’ they will eat that as well, and if Mom dies, she becomes dinner. Now that’s gratitude! Most earwigs, such as the common species found here, are nocturnal and feed by actively hunting live prey. This consists of arthropods, scavenging on plant and animal material, or by harvesting fresh plant materials, such as fruit and foliage. Prey may include: plant lice, aphids and flies, while plant preferences include: many ornamentals, such as sunflowers, berries, grapes, peaches, roses, zinnias, dahlias, and clover, etc.

The most obvious and perhaps scary feature of these small insects are the pincers at the end of the abdomen. In the male, they are curved and threatening to look at. The female sports a much less curved pair which doesn’t evoke the same response from us. The pincers are flexible and functional. They can be used to grip prey, as a defense mechanism, or may also be employed as part of the mating ritual. When threatened, they often lift them over their backs, much as a scorpion would, to ward off predators. Some species can emit a foul-smelling fluid which can be cast up to four inches, at threatening predators, as an additional defence strategy.

Earwigs may be found anywhere dark or damp, and this causes us to react as they scurry away in our homes, gardens and even footwear, if left in a dark, damp place. They can nip the skin but they are not aggressive, however, their odd appearance makes them appear more repulsive than they actually are.

Love them or hate them; they are a part of our lives, whether we want them or not!

Geoff Carpentier is a published author, expedition guide and environmental consultant. Visit Geoff on-line on LinkedIn, Facebook and Instagram.