Earwigs are common insects often found in gardens and sometimes indoors. They are known for the prominent pair of “pincers” or forceps at the end of their abdomen. This unique feature frequently sparks both curiosity and apprehension.
Anatomy and Types of Pincers
Earwig pincers, or cerci, are hardened, forceps-like structures at the rear of their segmented abdomen. Composed of chitin, the material of their outer exoskeleton, these appendages are maneuvered effectively by the earwig’s flexible, muscular abdomen. Their appearance varies noticeably between male and female earwigs.
Male earwigs typically have pincers that are more curved, robust, and sometimes asymmetrical. Female earwigs have straighter, more slender, and parallel pincers. These differences become apparent as nymphs mature into adults. The distinct shapes relate directly to their varied biological functions.
Diverse Uses in Earwig Life
Earwigs utilize their pincers for several crucial biological purposes. One primary function is defense; earwigs raise their pincers to deter predators like birds, spiders, or other insects. While their pinch may startle an attacker, it is generally not painful to larger creatures. Some species can also release a foul-smelling liquid from abdominal glands as an additional deterrent when threatened.
Beyond defense, these pincers play a role in predation and hunting. Earwigs are omnivorous, and some species use their cerci to capture and manipulate small prey such as aphids, mites, or other soft-bodied insects. The pincers act like mini-claws, helping them grasp and hold onto their meals.
Mating rituals also involve the specialized use of pincers, particularly by male earwigs. Males use their curved pincers to grasp and hold the female during copulation. Courtship displays can also include the male tapping and stroking the female with his forceps. The length and shape of male pincers can even influence mate selection and competitive encounters between males.
A more specialized, though less common, use of the pincers is in assisting with wing folding. Many earwig species possess membranous hindwings that are intricately folded up to 40 times beneath their short, leathery forewings. The pincers help unfold and refold these complex, fan-like wings. This mechanism allows for compact storage of their wings when not in flight.
Do Earwig Pincers Harm Humans?
Despite their intimidating appearance, earwig pincers pose minimal threat to humans. While earwigs can pinch, this typically occurs only if they feel threatened, are handled roughly, or are accidentally trapped against the skin. The sensation is usually described as a minor nip, similar to a fingernail pinch, and is more surprising than genuinely painful. It rarely breaks the skin.
If the skin is broken, which is uncommon, it usually results in two small red marks that can be treated like any minor scratch by cleaning the area with soap and water. Earwigs are not venomous and do not possess stingers. They also do not transmit diseases to humans. While earwigs can carry germs from their environment, the risk of infection from a pinch is exceedingly low if the area is cleaned. Direct physical harm from earwig pincers is generally negligible.