Earwigs

 

Photo by: K. Leeker

In Roald Dahl’s children’s book “George’s Marvelous Medicine” Georges’ grandmother encourages him to eat unwashed celery with beetles and earwigs still on it. “A big fat earwig is very tasty,” Grandma said, licking her lips, “but you’ve got to be very quick, my dear, when you put one in your mouth! It has a pair of sharp nippers on its back end and if it grabs your tongue with those it never lets go. So, you’ve got to bite the earwig first, chop chop, before it bites you!”  This nightmare-inducing excerpt from a children's book is indicative of the myths surrounding the oft-considered creepy, earwig.

Most of us have encountered an earwig at some point in our lives, usually in our gardens, but also occasionally in our homes. Many would agree they are intimidating with those large pincers pointed upwards in a sign of defense. Earwigs have been around for over 200 million years, and the ancient fossils looked very similar to our current earwigs. There are nearly two thousand species occurring on every continent except Antarctica, with twenty-five species found in North America and ten of those found in the United States. The most common one to be encountered in our area is the non-native European earwig, first introduced to the United States in 1907 when it was found in Seattle, Washington. They spread very quickly throughout the country and are now frequently found around our homes and gardens. They are relatively small insects measuring less than ¾ of an inch, the body is dark brown with a reddish head and pale brown legs. They have membranous wings protected by short forewings. While they are capable of flying they rarely do. The most recognizable characteristic of the earwig is the large forcep-like pincers on the tip of the abdomen. Males have curved pincers, whereas females have straight pincers. While these appendages look dangerous, they are not harmful unless you are the insect prey they are after. Yes, they can pinch us with them, and I have been pinched several times,  it will not break the skin unless you are a very young child or elderly and even then it would be superficial. In addition, they are not known to spread any diseases to humans or other animals.

The name earwig is derived from an Anglo-Saxon word that means ear creature. Sounds pleasant doesn’t it? Many scientists believe their name is derived from the common superstition that earwigs crawl inside your ear and burrow into your brain to lay eggs. When the eggs hatch the presence of the young will drive you insane. While it is not likely to have one of these insects climb into your ear, it is not impossible. There is documentation of earwigs entering the ear canal of unsuspecting people. Most often this occurs at night when the earwig is most active and by morning it is searching for a dark, damp place to hide….a human ear would fill this need. Upon waking your ear feels strange as if something is crawling around in there. A loved one shining a flashlight into your ear informs you that you have an uninvited guest taking up residency. A trip to the doctor and a relatively minor extraction will bring welcome relief. I can imagine when humans first resided in caves and other sheltered areas exposed to all manner of creatures, it was probably commonplace to have an insect crawl inside your ear opening. Then imagine this knowledge being passed down for thousands of years until it persists as fact in our culture.

Occasionally these insects appear in massive hoards. In 1755 they appeared in vast numbers near Stroud, Gloucestershire, UK where they took shelter in cracks and crevices in human dwellings. Their numbers were so large they would fall from the ceilings covering the floors below. In more recent times, in 2006, throughout the Blue Ridge Mountains, a plague of millions of earwigs caused much annoyance to residents as they hung around for over two years! No one seems to know why or how to predict when plagues of earwigs will occur, but fortunately, it is a rare occurrence.

However, they may occur in larger numbers than we may like in years when we have heavier than usual rainfall, creating the moist conditions these bugs favor. During these rainy years, we may encounter them in the cracks and crevices of picnic tables, lawn furniture, underneath chair cushions, waste bins, compost piles, window frames, and other sheltered areas. Nocturnal by nature, they are rarely encountered during the day unless you happen to disturb their hiding spot. Most species are scavengers, but they will also eat most any plant matter as well as soft-bodied insects like aphids. The European earwig is known to cause damage to various vegetable crops such as cauliflower, cabbage, celery, chard, potato, beets, and cucumbers as well as many others. In massive enough numbers, they may cause damage to corn as they feed on the silk of the plant. Usually, they do not occur in numbers large enough to cause significant damage. There are good benefits to these insects as well as bad. They do feed on aphids, scale insects, and other insects known to cause much damage to plants.

Earwigs do not tolerate extreme cold when outside, this causes many to move into human structures seeking shelter. Those that do remain outside create a burrow underground where a male and female will live together. Mating occurs at this time. In the spring when the female is ready to lay her eggs, she will evict the male. After laying up to eighty eggs, she will guard them from predators. One of the few insects to express maternal care for their offspring, she will clean fungi off the eggs by consuming the fungus. This action leaves behind an antifungal enzyme that helps the eggs resist deadly fungi. Once hatched the mother will remain with the nymphs until they shed their skin twice. During this time, she will leave the young long enough to retrieve food, bring it to the burrow, and feed all those hungry mouths. She will also regurgitate food into their mouths. Earwigs only live about one year, therefore after months of working so hard to care for her young, the mother will perish within the nest as the ultimate sacrifice. The young will feed on her corpse and leave the burrow fat, healthy, and ready for life on their own. ‘

If you find yourself with an earwig infestation in your home, try to eliminate areas where they can enter. Fix leaky faucets and air conditioning units.  Eliminate damp, moist conditions consistent with mulch, wood chips, boards, bricks, and gravel against the house. If the problem persists or is of a large enough scope to be unmanageable you may need to call a professional to spray for them. If you choose to use insecticides yourself, always follow instructions and keep in mind many beneficial insects will die along with your target insect. For me, they are fascinating creatures, however, I have no intention of sampling some earwig-infested celery!