Diagnosing European earwig

A chewing insect introduced from Europe that can damage seedling crops and contaminate grain. Mainly found in the southern wheatbelt.

Shiny black insects with light brown legs and rear pincers (Male left, female right)
Irregularly chewed lucerne leaving petioles and wispy dead leaf veins
Chewed canola plants.
Earwig paddock damage

What to look for

    Paddock

  • Seedling stumps or shredded leaves, usually in patches and areas with higher stubble or pasture residues.
  • At times, European earwigs are a nuisance around buildings and can spread into adjacent crops.

    Plant

  • Leaves are irregularly chewed leaving petioles and wispy dead leaf veins.

    Insect Adult

  • Shiny flattened insects with a dark brown body and light brown/yellow legs and pincers. Juveniles are smaller and paler.
  • Earwigs are nocturnal but can be found hiding under rocks and plant material during the day.

What else could it be

Condition Similarities Differences
Diagnosing vegetable beetle damage Chewed plants, seedling death European earwigs chew the leaf blade and tend to leave stems, petioles and veins, and are usually found near affected plants
Diagnosing cutworm in cereals Chewed plants, seedling death European earwigs chew the leaf blade and tend to leave stems, petioles and veins, and are usually found near affected plants
Diagnosing weevils in canola Chewed plants, seedling death European earwigs chew the leaf blade and tend to leave stems, petioles and veins, and are usually found near affected plants
Diagnosing slugs in crops Similar plant damage with shredded leaves European earwigs are usually found near damaged plants, and are not restricted to heavy soil types like slugs
Native earwigs
Similar appearance Native earwigs are not found in high numbers and do not congregate together

Where did it come from?

  • The European earwig is native to Europe, and was first found in Western Australia in 1990. It is well established in towns, but distribution is patchy in the agricultural area.
  • Adults have wings but they seldom fly and are mainly spread by human activity. They are easily transported in machinery and vehicles, containers and plant material.
  • They usually breed once a year. The length of the lifecycle depends on temperature. At 25°C, the development from egg to adult takes nine to ten weeks, but at 15°C it takes up to five weeks longer.
  • European earwigs feed on a wide range of food types such as organic matter, fruits, ornamental plants, vegetables, flowers, seeds and live and dead insects, including earwigs and caterpillars.

Management strategies

Stubble management
Stubble management
Spraying insecticide
Spraying insecticide
  • Currently there are no broad-acre insecticides registered for use in broadacre crops.
  • Grain contamination when harvesting swathes can be minimised by harvesting during the day.
  • Reducing retained stubble decreases populations of this pest.
  • Insecticides registered for use around the exterior of buildings and structures will reduce spread into adjacent crops.

Where to go for expert help

Page last updated: Monday, 1 May 2017 - 11:54am