Earwigs

Scientific Name: Dermaptera

How to identify an earwig

Earwigs have an elongated and flattened or cylindrical body. They can be winged or wingless, and they have chewing mouthparts. The abdomen is long, flexible and telescopic (segments of the abdomen may be drawn into one another like a telescope). The two forcep-like cerci on the end of the abdomen are heavily sclerotised (hardened) and vary in shape and size between species. The forewings, called 'tegmina', are short and lack veins. The large, membranous and semicircular hindwings fold up fan-like under the tegmina and can be unfurled or folded very quickly.

They come in a range in colours, including: yellow, yellow brown, orange brown, reddish brown, dark brown and black, and sometimes are a combination of these.

Females can be readily distinguished from males as they are usually smaller, have simple forceps and eight visible abdominal (hind-body) segments as opposed to males, which have ten.

Where are earwigs commonly found?

Earwigs may be found in protected, moist environments in leaf litter and all kinds of debris on the ground, under bark, under stones, between leaves and some even inhabit crevices at the base of tightly packed and overlapping leaves of Pandanus. Earwigs are usually nocturnal and attracted to lights at night.

Why are earwigs considered a pest?

Most Australian earwig species are not significant as pests. Many species can produce a noxious fluid as a defence. Some can become nuisance pests if present in large numbers. One pest species is the introduced European Earwig (Forficula auricularia), which can be a serious pest of gardens and vegetable crops and is relatively common around suburban homes. Alternatively, an Australian earwig Labidura truncata may be beneficial to agriculture, as it has been observed attacking codling moth (Cydia pomonella) larvae, a pest of fruit crops such as apples, peaches and pears.

What is the biology and lifecycle of an earwig?

Female earwigs care for their eggs and young nymphs, which is an unusual trait in most non-social insects. Females dig a short burrow on the ground beneath leaf litter and debris where they lay their eggs and which they defend from intruders. The females care for the eggs by collecting them up if they become scattered and clean the eggs by licking off fungus and parasites. After the young nymphs hatch the female feeds them up to the second or third moult, when they can then look after themselves, and at this stage the females may even become cannibalistic.