Earwigs, with their distinctive pincer-like appendages, are common insects found in gardens and homes across the globe. Their somewhat intimidating appearance often sparks curiosity about their nature and their place among other insects. These nocturnal creatures frequently hide in moist, dark places during the day, emerging at night to feed.
Their Place in the Insect Kingdom
Earwigs belong to the scientific order Dermaptera. The name Dermaptera itself is derived from Greek words meaning “skin wing,” referring to their unique wing structure.
This order is considered relatively small within the vast insect class, comprising about 2,000 known species across 12 families. Earwigs are found on every continent except Antarctica, with most species inhabiting tropical and subtropical regions. In North America, there are approximately 20 species.
Defining Features and Distinctions
Earwigs are readily recognized by several key physical traits. Most notably, they possess a pair of prominent, forcep-like appendages called cerci at the end of their abdomen. These cerci, which can be curved in males and straighter in females, are used for defense, grooming, and courtship. Earwigs typically have elongated, flattened bodies and slender antennae.
While many species possess wings, earwigs rarely fly. Their forewings are short and leathery, acting as protective covers for the large, semicircular hind wings. These delicate hind wings are intricately folded like a fan beneath the forewings when not in use. Earwigs are characterized by their distinct cerci and wing structure.
Evolutionary Connections
Understanding the evolutionary connections of earwigs requires looking at their shared ancestry with other insect groups. Earwigs are part of a larger grouping of insects called Polyneoptera, which includes orders like grasshoppers, crickets, cockroaches, and termites. While their exact position within this group has been subject to ongoing research, modern phylogenetic analyses, particularly those using molecular evidence like DNA, help clarify these relationships.
For a long time, their closest relatives were thought to be Orthoptera, the order of grasshoppers and crickets. However, more recent studies, including a 2018 phylogenetic analysis, suggest that earwigs (Dermaptera) may be most closely related to angel insects (Zoraptera). Other research has also explored connections to stoneflies (Plecoptera). These relationships indicate that earwigs share a deep evolutionary history with several well-known insect groups, diverging from common ancestors millions of years ago.
Common Misunderstandings
One of the most persistent misunderstandings about earwigs stems from their common name. The myth that earwigs crawl into human ears and burrow into the brain to lay eggs is a long-standing misconception. This belief is entirely false, as earwigs have no interest in doing so and pose no such threat to humans. While an earwig might accidentally enter an ear, this is no more likely than with any other small insect.
The name “earwig” likely originated from Old English words meaning “ear insect” or “ear beetle.” One popular theory suggests the name refers to the unique shape of their unfolded hind wings, which some believe resemble a human ear. Another possibility links the name to historical associations with ears of corn or the pincer-like cerci resembling goldsmiths’ tools for piercing ears. Dispelling these myths helps to clarify that earwigs are simply another fascinating group of insects, not malicious invaders.