Mites & spiders


Mites are minute (usually less than 1mm) arachnids with eight legs when adults. They are often pests of animals and plants, infest stored food products and in some cases transmit diseases.

Mites are a risk for Western Australian primary producers as they impact upon market access and agricultural production. 

Western Australia is free from some of the world's major agricultural mite pests. Biosecurity and management measures on your property are vital in preventing the spread of mites.

The Department of Agriculture and Food, Western Australia provides:

  • biosecurity/quarantine measures at the State border to prevent the entry of mites.
  • advice on widespread mites present in the State.

For advice on mites please search our website, Western Australian Organism List or contact our Pest and Disease Information Service (PaDIS). For diagnostic services, please contact our AGWEST Plant Laboratories or Animal Health Laboratories.


Spiders are eight legged arachnids. They are not agricultural pests and do not spread disease or damage crops or food products. Spiders can play a beneficial role by feeding on pest insects. There are hundreds of species of spiders in Australia, with very few spiders that are potentially harmful.

Contact the Western Australian Museum for further information on spiders or Poisons Information on 13 11 26 for treatment of severe bites.



  • 25 June 2014

    Mites of the Tetranychidae family (commonly known as spider mites) include some important pests of economic concern to agriculture and forestry.

  • 28 October 2014

    Mites (Acari) are arthropods, a group that includes insects and spiders. Some mites are large enough to be visible to the naked eye while others can only be seen with a hand lens or microscope.

  • The red dot on its back distinguishes blue oat mite from redlegged earth mite.
    17 April 2015

    Blue oat mites (BOM) are sap-sucking pest of crops and pastures. Canola and peas are particularly susceptible. Often co-exists with redlegged earth mites.

  • Lupin cotyledons become thickened and silvered
    17 April 2015

    Balaustium mite is a sucking pest of crops. Crops usually outgrow damage unless stressed.

  • Adults are 0.6 millimetres long, red-brown with distinctly longer forelegs
    17 April 2015

    Brown wheat mite is an uncommon sap-sucking pest of cereals that is most active in dry warm weather.

  • Leathery cotyledons
    17 April 2015

    Redlegged earth mite (RLEM) is a sap-sucking pest of crops and pastures. Canola and peas are particularly susceptible. They often co-exist with blue oat mites.

  • 17 February 2016

    There are many hundreds of species of spiders in Australia which play a beneficial role in our environment by eating insect pests.

  • 22 December 2014

    The most common mite pest of strawberry crops is two-spotted mite (Tetranychus urticae), also known as spider mite or red-spider mite.

  • 1 June 2016

    European red mite feeds on leaves of fruit trees especially apples. This can result in premature leaf fall which affects fruit tree vigour and fruit quality.

  • Reddish-grey, pie-shaped body, with red legs and two long forelegs
    20 May 2015

    Bryobia mite, also known as clover mite, is a sap-sucking pest of broadleaf crops and pastures, that can seriously damage canola especially where there has been a 'green bridge' consisting of clove