http://www.discoverlife.org/nh/id/20q/Andrena_female.xml ---> https://www.discoverlife.org/nh/id/20q/Andrena_female.xml &pull 20q v5.209 20240824: Error 501 Protocol scheme 'https' is not supported (LWP::Protocol::https not installed) https://www.discoverlife.org/nh/id/20q/Andrena_female.xml
IDnature guides | |
Overview |
- 4 suborders: Archidermaptera, Forficulina, Hemimerina, Arixenia; 10 families; 1800 species.
The scientific name refers to the leathery fore wing (dermatos: skin, pteron: wing)
(Tree of Life).
- "The name Dermaptera, derived from the Greek "derma" meaning skin and "ptera" meaning wings,
refers to the thickened forewings that cover and protect the hind wings."-- (N.C. State University Entomolgy Course)
- Earwig is the common name in many languages such as Dutch, German, Swedish, Danish,
Portuguese, French, Spanish, and English. The name earwig stems from a common belief
that the insect likes to crawl into people’s ears at night to lay eggs in the brain.
There is no evidence to support this superstition except that Dermaptera like dark,
humid crevices (Tree of Life).
|
Identification |
The common Dermaptera are elongate and slender and dark brown in color.
Sometimes they have a light brown or yellow pattern but colors such as metallic
green are real exceptions (Tree of Life).
Their length is commonly 10 to 14 mm in length with the cerci adding another 4 to 9 mm.
The winged species have two sets of wings. The first set is a small, horned, leathery
textured set, called tegmina, that is used as covering sheaths for the hind wings (Tweedie 1977).
The hind wings are large, membranous, semi-circular discs with an elaborate vein pattern
radiating from a common point. But even the winged species rarely fly (Hickin 1964).
The hind wings of Dermaptera are folded in an amazingly complex way; they are first folded
fan-like then longitudinally and tucked under the fore wings.
The cerci are modified as forceps which aid in the complex wing folding.
The forceps are also used by some species for predation, defense against predators,
and grasping their partner during copulation. Dermaptera's compound eyes may be
large, small, or absent depending on the species (Gullan 1994). Their mouthparts
are adapted for biting, which aides in predation or parasitism
(Tree of Life).
The antennae are short and are used for exploring the surface area just ahead of them (Tweedie 1977).
|
Phylogeny |
Taxonomic Category
| Scientific Name
| Common Name
|
Phylum
| Arthropoda
| Arthropods
|
Class
| Insecta
| Insects
|
Order
| Dermaptera
| Earwigs and Pincerbugs
|
|
|
Geographic distribution |
Earwigs are distributed worldwide except in polar regions and are most common
in the tropics (Tree of Life).
They are very common in Europe (mostly in the southern parts), but also
occur in North America along the southern coast as well as the pacific slope
(N.C. State University Entomology Course).
| North America
| Worldwide
|
Number of Families
| 4
| 10
|
Number of Species
| 20
| ~1800
|
|
|
Natural history |
- Evolutionary History
The fossil record for Dermaptera begins around the beginning of the Jurassic
(208 MYA) and contains about seventy specimens. The fossils are very similar
to recent specimens except for segmented cerci. Evidence suggests that the
Dermaptera probably stemmed from the Protelytroptera (resembling cockroaches)
of North America, Europe, and Australia from the Permian (290MYA). However,
there have been no fossils found during the Triassic when the morphological
changes from Protelytroptera to Dermaptera probably took place (Tree of Life).
- Feeding
Nymphs are fed by the mother during the first three instars. Adult feeding
preferences vary greatly depending on the species. The common earwig typically
feeds on dead and decaying vegetation and occasionally feeds on live plants.
Some groups are parasitic, such as the Arixenia, which feed on the skin
secretions of bats in tropical caves or the Hemimerina which feed on the skin
of giant rats in Africa (Tree of Life).
- Life Cycle
Female earwigs lay about 30 eggs in a burrow under debris. The mother tends
to the eggs, frequently licking off fungi and parasites. Larvae develop
gradually by successive molts (Tree of
Life). The parental care by the mother is continued for 2-3 instars, at
which point the mother may cannibalize her young (Gullan 1994). The nymphs
resemble the adults except for a lack of wings. The adult Dermaptera has one
life-cycle per year, hibernating during the coldest months in their burrows.
In the spring the male is ejected from the burrow so the mother can care for
the soon hatching nymphs (Gullan 1994). Common Dermaptera are oviparous but
viviparity is known in Hemimerina and Arixenia (Tree of Life).
- Economic Importance
Earwigs may do some damage in gardens by eating vegetation (they have been
known to damage ornamental plants and fruit and vegetable crops) but may also
eat other insects. They are most likely harmless but can become a nuisance
in the household if there is a lack of suitable crevices outdoors (Tree of Life).
|
How to encounter |
Dermaptera can be found in gardens, under thick shrubs, and around decaying matter.
They frequent humid crevices and search in close contact with surfaces.
|
Links to other sites |
- For natural history information about Dermaptera, visit John R. Meyer's site at NC State University, Department of Entomology.
- For Ohio State University's extension fact sheet on earwigs, visit William F. Lyon's website.
|
References |
- Gullan, P.J. and P.S.Cranston. The Insects: An Outline of Entomology. Chapman and Hall; 1994.
- Hickin, NormanE. Household Insect Pests. Huthinson; 1964.
- Tweedie, Michael. Insect Life. Collins Countryside Series; 1977.
|
Acknowledgements |
This page written by Michael Howell, University of Georgia, Athens.
Thanks to Sabina Gupta, Denise Lim, and Dr. John Pickering for technical and web support in developing this page.
|
|