Dermaptera : Forficulidae

Forficulidae

The Forficulidae have an elongate, cylindrical body. They are doted with grinding-type mouthparts. The elytra are very short and strongly sclerotized which completely protects the wings when at rest. The flattened abdomen is strongly sclerotized and bears a pair of bulky cerci modified into forceps. Like most Dermaptera, the Forficulidae are nocturnal, rarely fly and often form groups of about a dozen individuals.

Forficula auricularia (Linnaeus, 1758)

Earwig
Forficula auricularia : adulte
Forficula auricularia : ponte

Morphology

The adult is brown, about 15 mm long, with head and thorax clearly visible. The antennae are long, borne anteriorly. The elytra, short and covering the hindwings, are only très rarely deployed. The abdomen is uncovered and highly mobile. It ends in claw-like cerci .
The larva is similar to the adult but wingless and with lighter coloring.

Biology and behavior

In summer mating takes place and then the female lays her eggs. The larvae give rise to adults some months later. With the first cold spells and frosts of autumn (around October), the earwig burrows into the ground to hibernate. Most of the males die in winter, whereas the female of the year survive. About one month later, she digs a small burrow for a den, stays isolated and lays a few dozen white eggs, rounded and translucent (a maximum of about 60).
Towards mid-May the larvae hatch. The female attentively looks after her eggs and her larvae, until the last of four molts the larvae undergo. The young adults generally emerge in July. They remain active until the first frosts arrive.

Habitat

This is a common insect, highly widespread.
In daytime, the earwig avoids light and spends most of its time in cracks in the ground, under bark of dead wood, in the hollows of flowers or between the petals of large flower heads (roses for example). At night, it comes out of its shelter and goes in search of food (aphids, Psylla and so on).
Generally it is considered as a gardener’s help because it consumes a large number of harmful insects. It also eats plant material that is overripe or starting to decompose such as flower petals, fruit (peach, plum or apricot) and vegetables as well which earns it a reputation also of being a pest

Modification date: 24 April 2024 | Publication date: 30 June 2011 | By: Evelyne Turpeau, Maurice Hullé, Bernard Chaubet