There are nearly 2000 species of earwig in the world, but only 4 species occur in the UK. The four species of earwig present in the UK are: Common, Lesser, Lesne’s and Short-winged. The Common Earwig has the greatest distribution and can be found throughout the UK. The Lesser Earwig can only be found in the southern half of the UK.
The Lesne’s Earwig is less common and is once again only found in the southern half of England, while the Short-winged Earwig is only found on the South-East coast.
The Earwigs common name is derived from old English, with ‘ēare’ meaning ear and ‘wicga’ meaning insect. This is a term that may have arisen from the resemblance of their wings to the shape of a human ear, although it may also come from the legends of earwigs crawling into people’s ears – I am glad to say they don’t do this, it is just a myth!
Some earwigs have no wings (known as apterous), but in the UK, all four species have two pairs of wings. The forewings are leathery, forming short wing cases, and the hind wings are large, membranous and semi-circular. Their hind wings are pleated concertina-fashion, about 40 times, and held under the wing cases. These hind wings are one of the most compact wing folding examples seen in insects and they open to roughly ten times the size!
Because they are stored so compactly, it does not compromise their ground mobility or increase their size unnecessarily. Taking inspiration from nature, researchers have looked at the complex folding of earwig wings and how their structure and function may be applied to design and engineering projects.
Earwigs also have characteristic cerci (a pair of appendages at the end of the abdomen), which are modified into a set of pincers. Pincers are usually bigger in males and are more curved when compared to the relatively straight pincers in females. Pincers are used for a variety of tasks, such as defence, grabbing prey, and mating.
Earwigs typically mate in the autumn, with the adults approaching each other (I imagine somewhat warily!) backwards and mating end-to-end. The male sperm can be retained in the female for a few months before fertilisation takes place.
The earwig is one of the few non-social insects to show dedicated parental care of offspring. After mating, the male departs (typical I hear all you girls shout!) and the female lays 50-90 white eggs in a nest the ground. During the winter she defends the eggs against predators and keeps them free of mould by licking them.
The eggs hatch in spring and the female cares for the larvae (nymphs) during the early stages. Earwigs undergo a type of development known as incomplete metamorphosis, in which the nymphs progress through a series of moults. The stages between moults are known as 'instars'.
Now – guess what a baby earwig is called? They are called Wiglets! (A wonderful Scrabble word!) These Wiglets look like smaller versions of adults at all stages.
The female will have lost her maternal instinct when the Wiglets reach their second instar, so it is best that the young leave by then, as they otherwise potentially run the risk of being eaten by their mother!
If only it was that easy to get your children to leave home. Just organise a drinks party and say, “anyone like a Twiglet to eat” and watch the kids rush out of the house!
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