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Kids' Inquiry of Diverse Species

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.

 
University of Michigan Museum of ZoologyNational Science Foundation

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. "Dermaptera" (On-line), Animal Diversity Web. Accessed September 02, 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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