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Local animals in this group:

Dermaptera

What do they look like?

  • Sexual Dimorphism
  • sexes shaped differently
  • Range length
    4.0 to 25.0 mm
    0.16 to 0.98 in

Where do they live?

Earwigs are found in temperate regions to the tropics and subtropics. Of the approximately 1,800 species that exist worldwide, 28 species are found in the United States, and 6 species are found in the Great Lakes region. Those in the Great Lakes region are introduced from southern areas.

What kind of habitat do they need?

These nocturnal insects hide in cracks, crevices, under bark, and in debris during the day. If present in sufficient numbers, earwigs can be found hiding almost anywhere in the homes of humans.

How do they grow?

Metamorphosis is simple with three stages of development. Temperature is important in controlling the rate of development which can range from 20 to 70 days. In the spring, the female will lay eggs. By late summer to early fall, the nymphs are fully grown. Adult earwigs overwinter.

How do they behave?

Some species of Dermapterans have glands dorsally located on the third and fourth abdominal segments that contain a foul-smelling fluid. When provoked, the earwig will squirt this fluid for the sake of protection. They can squirt fluid 7 to 100 mm.

Although they have chewing mouthparts, earwigs are not known to bite when threatened or handled. If earwigs are handled, they can inflict a painful pinch with their cerci since their abdomens are quite flexible. The cerci are used for defense, prey capture, mating, and wing unfolding.

For those earwigs that have them, their wings are fully functional. In addition, earwigs are not known to crawl long distances. However, earwigs have spread rapidly thoughout parts of North America via hitchhiking, hiding in almost every item that potentially can be transported by humans.

What do they eat?

Earwigs feed mainly on dead or decaying vegetable matter, and they will feed on living plants. They eat plant leaves, algae, fungi, sprouts and seedlings, flower petals, pollen, and corn silks. A few species are predators, eating other live insects and small invertebrates. The earwig will grasp its prey with its cerci, the pinchers at the end of its abdomen, and then bend so that the prey is within reach of its mouth. Earwigs will also scavenge dead insects and small invertebrates.

What roles do they have in the ecosystem?

Dermapterans are contributors to biodegradation in that they are feeders of decaying organic matter.

Species (or larger taxonomic groups) used as hosts by this species
  • bats in southeast Asia
  • South African rodents
Commensal or parasitic species (or larger taxonomic groups) that use this species as a host
  • bats in southeast Asia

Do they cause problems?

Some earwigs may cause damage to flowers and vegetables, ornamental tress and shrubs. They are especially fond of corn. They have even been found in honey in beehives. When their populations increase, earwigs are found in homes, hiding in household items, foodstuffs, and most any other place, much to the disdain of humans.

How do they interact with us?

Earwigs eliminate decaying organic materials from the environment.

Some more information...

The name "earwig" is derived from ancient tales that these insects will enter the ears of humans. It was once believed that earwigs would crawl into the ears of sleeping humans, then bore into the inner ears and brain, thereby causing insanity. This legend is not true.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends.

biodegradation

helps break down and decompose dead plants and/or animals

bog

a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.

carnivore

an animal that mainly eats meat

chaparral

mid-altitude coastal areas with mild, rainy winters and long, dry summers. Dominant plant types are dense, evergreen shrubs.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

female parental care

parental care is carried out by females

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

marsh

marshes are wetland areas often dominated by grasses and reeds.

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

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oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Climbing plants are also abundant. There is plenty of moisture and rain, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

semelparous

offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

 
University of Michigan Museum of ZoologyNational Science Foundation

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. "Dermaptera" (On-line), Animal Diversity Web. Accessed April 16, 2014 at http://www.biokids.umich.edu/accounts/Dermaptera/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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