Earwig

Common earwig ( Forficula auricularia )

Earwigs ( Dermaptera ) are an order of insects, and are among the winged insects ( pterygota ).

Naming

From antiquity to the early modern period, the animals were pulverized as medicine against ear diseases and deafness administered. While the use was forgotten was the Latin name get auricula (from auris "ear" ). From this, the names are earwig in English and perce - oreille derived in French. However, earwigs are completely harmless to humans: The pliers, depending on the type, in the hunt for small insects, the wing unfolding and used for defense, not for pinching ears, as the name might suggest jokingly.

Others derive the name of catchy Öhrwurm from because of the needle eye, which resembles the tail vise of the male earwig. The incorrect suffix- worm received this insect because of their worm-like shape. In German-speaking countries the animals are known under various regional variations of their name.

General

The body length of the animals is usually 10 to 20 millimeters, some species can also be significantly larger, for example, the giant earwig ( Titanolabis Colossa ) with up to 50 millimeters in body length. The now -lost Saint Helena giant earwig ( Labidura herculeana ) is up to 80 millimeters long.

The front wing of the earwigs are hardened coarse and shortened ( in Derma (to) Ptera means ( gr ) derma as much as " leather "). To cover only the foremost part of the abdomen. The membranous hind wings are folded very compactly this deck wings. Only a few species of earwigs fly, some have the flight muscles and wings regressed completely. The abdomen ends in a pair of pliers to vice -formed abdomen threads, the Cerci, the strongly curved in males, in females rather are straight. This transformation has earned them the colloquial name " earwigs ". The guns are used for hunting, defense and as an aid during the deployment of the hind wings, and during copulation. Most species have well trained compound eyes. Simple eyes ( ocelli ) are always reduced.

Way of life

Earwigs prefer warm areas and habitats. They feed on plant parts and inventory waste, however, some species are predators and hunt smaller insects. Almost all species are nocturnal or crepuscular and spend the day under rocks, in tree bark or other hiding on.

The common earwig is omnivorous and is considered a beneficial insect, he eats as aphids or caterpillars. But it is also a pest when it corrodes soft parts of plants, such as flowers. But harder shells and fruit skins he can not nibble: he uses on grapes or apples from the only existing damage sites and is not responsible for them. On apple trees are often found him in the feeding programs of the codling moth. Other species such as the earwig, Labidura riparia, are pure carnivores and can contribute to pest reduction. Earwigs bring forth only one generation per year in question.

In addition to a very distinctive courtship behavior occurs in all species studied before brood care. The eggs and larvae are protected in self- cavities, but also in leaf grooves or under bark, often maintained and cleaned and partially even fed.

Taxonomy

The name Dermaptera was introduced by De Geer, originally for a group, includes the earwigs and grasshoppers, mantis and cockroach. Hence the name Dermatoptera, introduced by Burmeister (1838 ) is sometimes used to express that it refers exclusively to the earwigs.

The known 1800 species are divided into three groups, which differ mainly in the way of life and in the formation of the eyes and wings.

The eyes of the Forficulina are very well trained, most species have well trained wing. This group includes most of the species of earwigs, all of them occurring in Central Europe species:

• Labiduridae Earwig - Labidura riparia ( Pallas, 1773)

• Southern earworm - Euborellia annulipes (Lucas, 1847) (syn.: Anisolabis annulipes )

• Common earwig - Forficula auricularia Linnaeus, 1758
• Bushes earworm - Apterygida media ( Hagenbach, 1822)
• Two-point earworm - Anechura bipunctata (Fabricius, 1781)
• Forest earworm - Chelidurella acanthopygia (Gene, 1832)
• Chelidura guentheri Galvagni, 1993
• Chelidura thaleri resin, 1980

• Dwarf earworm - Labia minor ( Linnaeus, 1758)

In these animals, the compound eyes are small, missing blades. One known type is the living as Phorent at bats Arixenia esau in Malaysia. The viviparous Arixeninae live exclusively on or near bats on Malaysia and the Philippines.

The Hemimerina both the compound eyes and the wings are completely reduced. All species live on the giant pouched rats ( Cricetomys ) in Africa, where they probably feed on fungal skin and dandruff. It never could be shown that the Hemimerina would harm the giant pouched rats. Therefore, the Hemimerina must be described not as parasites but as mutualists or possibly as symbionts.

Phylogeny

The most preferable theory for the phylogeny of earwigs was erected in 1985 by EJ Popham due to genitalmorphologischen investigations. In his account of the Arixeniina represent only a taxon within the Forficulina dar.

Newer hypotheses of Haas and Kukalova - Peck ( 1995 and 2001) partially deviate strongly from this phylogenetic hypothesis from, where they are far better documented than that Pophamschen hypotheses, and are supported by molecular work.

Fossil evidence

Earwigs are known since the Jurassic. Imagines are represented by four species of the genus Forficula from various tertiary amber deposits (especially the Baltic amber of Eocene age). In Bernstein also inclusions have been found with larvae belonging to the genera Forficula, Labidura and Pygidicrana.

Endangering

The only kind on the global Red List of IUCN is the Saint Helena giant earwig Labidura herculeana (Fabricius, 1798). This occurred only on the Atlantic island of St. Helena and was not found for several decades. In 1995, again a pair of pliers abdomen (called Cercus ) have been found, live animals intended but only to about the second half of the 1960s.