Forficula auricularia

Geographic Range

European earwigs are native to Europe, eastern Asia, and northern Africa. Today, they can be found on all continents except Antarctica. Their geographic range continues to expand, and they have been found on an island in the Pacific Ocean (Island of Guadalupe).

• Biogeographic Regions
• nearctic nearctic
  • introduced introduced
• palearctic palearctic
  • native native
• oriental oriental
  • native native
• ethiopian ethiopian
  • introduced introduced
• neotropical neotropical
  • introduced introduced
• australian australian
  • introduced introduced

• Other Geographic Terms
• cosmopolitan cosmopolitan

Habitat

European earwigs are terrestrial organisms that live in mostly temperate climates. They are found in a very large geographic range and at elevations up to 2,824 m. During the day, they prefer places that are dark and moist to hide from predators. Their habitats include forests, agricultural, and suburban areas. During the mating season, females prefer a habitat abundant in rich soils as a place to burrow and deposit her eggs.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

• Other Habitat Features
• suburban suburban
• agricultural agricultural

Physical Description

European earwigs are brownish red in color and have elongated bodies that range from 12 to 15 mm long. They are equipped with 3 pairs of legs that are yellow to brown in color. European earwigs are well-known for the set of forceps, known as cerci, that protrude from the abdomen and are used for protection and in mating rituals. Forceps display sexual dimorphism, with those of the male being longer and more curved than those of the female. Forceps can also vary between males. Males with shorter and highly curved forceps are called brachylabic, while males with long, straighter forceps are called macrolabic. European earwigs have two antennae with 14 to 15 segments long that contain many important sense organs, as well as a fully developed set of wings.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes shaped differently

Development

Females lay fertilized eggs in a burrow dug into the soil. After about 70 days, the eggs hatch into first instar nymphs that remain in the burrow as the mother provides protection and food. When the young become second instar nymphs, they emerge above ground and find their own food. During the day however, they return to their burrow. Third and fourth instar nymphs live above ground where they develop into adults. Nymphs are similar to adults, but are lighter in color with smaller wings and antennae. As the nymphs progress from one instar to the next, they begin to darken in color, the wings grow, and the antennae gain more segments. Between each stage of development, the young molt by losing their outer cuticle.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

European earwig mating rituals usually occur in September, after which mating pairs can usually be found underground in a burrow into the winter. Courtship rituals involving the forceps play a large role in the mating process. Males wave and bob the forceps in the air, stroking and grasping the female. However, the forceps are not used in the actual mating process. If the female accepts the courting male, the male twists his abdomen into position for mating and attaches to the female. During mating, females move around and feed with the male attached to her abdomen. Fertilization of eggs takes place inside the female. Sometimes during mating, another male comes along and uses his forceps to fight off the mating male and take his place with the mating female. Males and females have multiple mates.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

European earwigs typically breed once yearly from September to January. Some females actually breed twice during this time frame. Eggs are fertilized internally inside the female and in late winter or early spring females lay 30 to 55 eggs. The offspring become independent two months after hatching and no longer require parental care. European earwigs reach sexual maturity at 3 months and are able to reproduce in the next breeding season.

• Key Reproductive Features
• seasonal breeding seasonal breeding
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous

Female European earwigs hibernate about 5 to 8 mm underground with their eggs, guarding them and keeping them clean from fungi and other pathogens using their mouth. The males are usually driven from the burrow in late winter or early spring and the female proceeds to lay her fertilized eggs. Once the larvae hatch in about 70 days, mothers provide their young with food by regurgitation until they reach the second.

• Parental Investment
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

A typical European earwig lives 1 year in the wild. Male earwigs often die before females, when they are kicked out of the burrow during the winter months.

Behavior

European earwigs are nocturnal. They hide during the day in dark moist places, such as under rocks, potted plants, wood piles, in fruits, flowers and other similar places. At night, they emerge to hunt or scavenge for food. They are weak fliers and therefore move around mostly by crawling and human transportation. European earwigs can be considered both solitary and colonial. Female earwigs live alone during the mating season, but during the other months of the year earwigs tend to congregate in very large groups.

European earwigs are considered to be a sub-social species as they provide parental care for their young. When European earwigs feel threatened or their offspring are threatened by a predator, they use their forceps as a weapon by snapping them quickly together.

• Key Behaviors
• terricolous
• nocturnal nocturnal
• motile motile
• sedentary sedentary
• solitary solitary
• colonial colonial

Home Range

There is little information on the home range of European earwigs. They are often found far from their point of origin due to human transfer from hiding in objects such as newspapers.

Communication and Perception

Adult European earwigs release a pheromone that attracts other European earwigs. Nymphs also release pheromones, which encourage mothers to provide care to their young. Forceps are also used as means of communication in mating and to show threatening behavior.

The segmented antennae of European earwigs contain many sense organs such as chemoreceptors that aid in sensing odors. These antennae also contain important tactile hairs which help the organism to get a sense of the surrounding environment. They also have compound eyes, enabling them to use sight as well to perceive their environment.

• Communication Channels
• chemical chemical

• Other Communication Modes
• pheromones pheromones

• Perception Channels
• visual visual
• tactile tactile
• chemical chemical

Food Habits

European earwigs are omnivorous organisms that are both scavengers and predators and feed using their chewing mouthparts. They feed on other organisms, both dead and alive, including aphids , maggots , mites , spiders , and protozoans . They also feed on both living and decaying plants, including lichens, algae, fruits and flowers.

• Primary Diet
• omnivore omnivore

• Animal Foods
• eggs
• insects

• Plant Foods
• leaves
• fruit
• flowers
• bryophytes
• lichens
• algae

Predation

European earwigs are preyed upon by several species of tachinid flies ( Diptera ), as well as certain beetles ( Coleoptera ). These include ground beetles like Pterostichus vulgaris , P. algidus , Carabus nemoralis , and Calosoma tepidum , as well as flightless tiger beetles ( Omus dejeani ). Other predators include toads ( Anura ), snakes ( Serpentes ), and certain birds ( Aves ) like Chinese monal pheasants ( Lophophorus ihuysii ). European earwigs have several different defense mechanisms used to avoiding predation. These include using their forceps as a weapon and using glands found in the abdomen to secrete chemicals that act as a repellent to predators.

Ecosystem Roles

European earwigs are common hosts to several different parasitic organisms including certain tachinid flies ( Thriarthria setipennis and Ocytata pallipes ) and nematodes ( Mermis nigresens >). They also serve as predators of other types of insects such as aphids ( Aphidoidea ) and some protozoa. European earwigs are also important scavengers in the ecosystem, feeding on almost anything that is edible.

Economic Importance for Humans: Positive

Aphids , a staple in European earwigs' diet, can cause great destruction to apple and pear orchards. European earwigs can help to control the population of aphids , thereby decreasing the amount of pest destruction to the crops.

• Positive Impacts
• controls pest population

Economic Importance for Humans: Negative

Since European earwigs tend to hide in dark, moist places such as newspapers or inside fruits, they are commonly carried into homes. European earwigs are essentially harmless to humans, but their unpleasant odor and appearance make them unwanted guests in the home. They can also cause damage to fruits and other crops as they feed on them. They are not as nearly destructive as aphids or other pests, but their feeding can still cause considerable damage to crops.

• Negative Impacts
• crop pest
• household pest

Conservation Status

European earwigs are not endangered or threatened.

Other Comments

A common misconception about earwigs based on their name is that they crawl into the ears of humans. This is actually a myth, and there are few known cases of earwigs actually crawling into the ears of people. The name earwig is actually derived from the fact that the hind wings of the organism resemble the shape of an ear.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

Morgan Vincent (author), University of Michigan-Ann Arbor, Catherine Kent (editor), Special Projects.

References

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