Earwig
Labidura riparia
A forceps-wielding sentinel in coastal rock crevices
The earwig lives under stones and driftwood in the coastal intertidal zone. A pair of pincers (forceps) at its abdomen tip — shaped differently by sex — is its weapon, used for defense and to subdue prey. Its forewings are reduced to short, leathery wing cases (elytra) covering only the front of the abdomen.
Key figures
- Length
- About 16–25 mm; dark brown to near black, flat and elongated
- Lifespan
- Nymphal stage lasts several months; adults live for close to a year, active across two seasons
- Habitat
- Under stones in the coastal intertidal zone, driftwood and accumulated organic debris
- Diet
- Omnivorous; feeds on small invertebrates, algal fragments and decaying organic matter
- Forceps
- Differ between the sexes — curved and asymmetrical in males, straighter in females
- Defense
- The forceps are used mainly for defense and subduing small prey, not for crawling into human ears
Life cycle
Egg (guarded by the female) → Nymph (multiple molts) → Adult
Ecological role
The earwig lives under stones and driftwood in the coastal intertidal zone, feeding on small invertebrates and organic debris — an unremarkable but common omnivorous link in the coastal food web.
Did you know
The old folk tale that earwigs crawl into ears is a myth — earwigs have no habit of entering ear canals, and their forceps are used only for defense and hunting, posing almost no threat to people.
Range
Temperate to tropical coasts worldwide; common along China’s coastline
Status
Common
Anatomy
- Forceps — A specialized structure at the tip of the abdomen, used to fend off predators and subdue prey; its shape differs between the sexes
- Short Elytra — The forewings are reduced to very short, leathery cases covering only the front of the abdomen, leaving the rest of the segments exposed
- Antenna — Slender and beaded, used to detect humidity and scent in rock crevices
- Head — Flattened, allowing it to squeeze into narrow gaps beneath stones and driftwood
- Abdomen — Flexible enough to curl upward, letting the forceps strike from over the back
- Legs — Short and sturdy, adapted for scurrying quickly over gravel and wet sand
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