Crop Insects



European Earwig

Forficula auricularia



European Earwig (Forficula auricularia)
? Agriculture Western Australia

Adult European earwigs are between 12 to 20 mm in length. They heve smooth and shiny dark brown bodies with pale yellow legs, pincers and shoulders. Males have curved pincers while females have long straight pincers. The nymphs are similar in appearance only smaller and paler than the adults.

European earwigs should not be confused with native earwigs. Native earwigs (several species) generally have reddish-brown foreparts and legs with a darker abdomen and pincers. They are widespread and feed mainly on leaf litter and other organic material. Native earwigs rarely cause any damage to plants.

European earwigs threaten high-yield crops. Farmnote No 9/95


Native Earwig (Gonolabis michaelseni)
? Agriculture Western Australia

Life cycle
The lifecycle of the European earwig is greatly dependant on temperature. The development time from egg to adult decreases in warmer climates ie, at 15? C their development into an adult is about 15 weeks, whereas at 25? C it is only 9 to 10 weeks. Adult females lay 20 to 80 white oval eggs in burrows in the topsoil. These eggs hatch two to three weeks later. There are six nymphal instars with the females protecting early instar nymphs. Later instar nymphs are left to fend for themselves and may even be consumed by adults. European earwigs are nocturnal and shelter in dark spaces during the day.
European earwigs tend to only become a problem if populations become large. It is believed that their numbers have increased in recent years due to greater use of mulching and ground covers. In high population situations they can devastate emerging crops. They can also damage mature crops.

After harvest, they migrate to cooler, darker and more humid locations under the windrows where they feed on the pods. When the windrows are put through the header to extract the seed, the harvest is contaminated with earwigs and often requires cleaning.

The European earwig is regarded as a nuisance or relatively minor domestic pest. However, it damages ornamental plants, vegetables and fruit. Homes are often invaded with damage to carpets and foodstuffs.
Around the garden, earwig numbers can be reduced by trapping the insects in an upturned flower pot filled with crumpled straw or newspaper. The earwigs will shelter in this during the day and can be killed, for example, by placing them in a black plastic bag in the sun for a day. For further information refer to Farmnote 9/95.