Pincher bugs: what are they, and why are there so many this year?

Jon Hammond.

A pincher bug on a spearmint leaf, with its cerci (pinchers) raised upwards in a defensive position.

If you have been finding lots of pincher bugs or earwigs in your house or yard this spring, you are not alone. It appears that 2024 has been a banner year for them. So let's look into what they are, and why there are so many this year.

Pincher bugs are insects with forcep-like structures at the end of their abdomen called cerci, and these cerci are of course the source of the name pincher bug. Or "pinchy bug," as little Kylah started calling them when she was three.

They are also called earwigs, a name that I like less, because it can reinforce a myth that they like to crawl into the ears of sleeping people. Apparently the name is derived from the Old English words "eare" for "ear" and "wicga" for "beetle," with no connection to an actual wig.

Some entomologists hypothesize that the name originated from the appearance of a pincher bug's unusual hind wings, which can somewhat resemble the shape of a human ear when unfurled. Yes, you read that correctly: pincher bugs have wings, though they don't use them very often.

But despite the speculation about their wing appearance, it seems more likely that the earwig name came from the myth about them crawling into ears, since their old French name, perce-oreille, translates to "pierce-ear."

In any case, pincher bugs have no abiding desire to climb into your ears. They do avoid light, so it's inevitable that a pincher bug may have ended up in someone's ear at some point, but it is NOT part of their normal lifecycle in any way.

Back to their wings: pincher bugs actually have amazing wings that open to be ten times the size they are when concealed. These wings are normally folded underneath wing covers on the insect's back. These wings are largely translucent, like creased cellophane, and they have to be flapped and shaken a little to fully extend.

Dermaptera, the order to which pincher bugs belong, literally means "skin wing" and describes their thin, membranous wings.

The revelation that pincher bugs have wings naturally suggests more questions: "So why don't they use them? When do they use this secret superpower?"

Entomologists believe that pincher bugs only use their wings when they are having difficulty finding food or mates, and want to move quickly to a more promising location. It seems that most pincher bugs limit themselves to crawling and climbing, and may live their entire lives without unfurling their magical wings even once. When exactly pincher bugs use their wings, and why they so seldom do, remains a bit of a poorly-understood mystery at this point.

The reason that pincher bugs are so abundant this year is more easily explained: they need moisture, and this was a wetter year, after so many dry years in the past 20 years. This year also comes on the heels of an even wetter winter in 2022-2023, so there has been more water available for the past 18 months or so, which benefits plants and insects (and all of us, for that matter).

Jon Hammond.

Pincher bugs or earwigs have had a bountiful spring, and have appeared in substantial numbers in the Tehachapi Mountains – occasionally making their way into homes.

It also was a fairly mild winter, in terms of low temperatures, without really hard freezes, so more insects like grasshoppers and pincher bugs survived the winter.

In addition to their unusual wings, pincher bugs differ from most other insects because the mothers actually take care of their eggs and young. The vast majority of insects lay eggs and then leave them to their own chances.

Not female pincher bugs. The mother will lay 20 to 80 eggs, and then she will stay with them until they hatch a week later, protecting them from predators, maintaining proper temperature and humidity, and even cleaning them continually to protect them from fungi. Like a female octopus, she will not even leave them to go eat.

After the young hatch, they will remain with their mother for safety until they molt once or twice. While colony insects like bees, ants and wasps care for their young, this kind of behavior is very rare among non-social insects.

Like some of our most ubiquitous insects, the pincher bugs that we commonly encounter are not native to North America, but were accidentally introduced from Europe.

Gardeners often dislike pincher bugs because they will eat tender young shoots, leaves and flowers. But they are not always a pest – pincher bugs also feed on aphids, providing predator services in some instances.

Despite having a pair of tweezers attached to their rear end, pincher bugs don't usually use them, even when you pick them up. And if they do, it is a very mild pinch that doesn't hurt. Ladybugs, on the other hand, can actually bite hard, and sometimes will for a short period in the spring when they are dispersing, but pincher bugs are actually pretty easy-going, and generations of small children have picked them up and collected them without getting pinched.

Like antlers on a buck deer, a pincher bug's cerci may be partly for display, and males do tend to have larger, more curved pinchers than females.

There are more pincher bugs this spring, but their numbers will subside as summer gets hotter and drier. If you find them in your house, these largely-nocturnal creatures aren't out to get you, they're just looking for moisture and to avoid the sun.

Keep enjoying the beauty of life in the Tehachapi Mountains.

Jon Hammond is a fourth generation Kern County resident who has photographed and written about the Tehachapi Mountains for 38 years. He lives on a farm his family started in 1921, and is a speaker of Nuwä, the Tehachapi Indian language. He can be reached at [email protected].