Tuesday, 5 November 2019
Name: Eriophyid mites – gall, bud, rust and erinose mites
There are over 300 known species of mites that fall under the name ‘eriophyid mite’, many are named for the host they are found on or for the symptom they cause e.g. tomato russet mite, russet mite, rust mite, gall mite, redberry mite, and many more. They infest a wide variety of Field and greenhouse crops as well as weeds and native plants. They can be serious pests of certain crops.
Egg: Laid on leaf or among buds, they can be spherical, elliptical, colourless, translucent or white.
Immatures: Microscopic. Similar in appearance to adults, can be lighter in colour. They cannot be reliably observed without a microscope.
Adult: Microscopic, up to 0.2 mm in length. Has greatly reduced body structure, torpedo shaped and appears worm-like with two pairs of legs at front of body. Maybe enclosed in galls.
Mites are spread on the wind and carried on clothing, machinery, other insects and animals. Under optimal conditions (27oC & 30% humidity) eggs will hatch in two days and young adults able to reproduce seven days later.
Many species damage growing tips, causing the new growth to be severely deformed and stunted, similar to broad mites. They sometimes attack the lower parts of the plant first and move upwards over stems and leaves. They do not produce webbing or secretions like spider mite species. Damage is often very species specific, with each eriophyid species only attacking a very small number of closely related plant species. Symptoms may include odd colour patches or bronzed appearance on leaf surfaces, rolling of leaf margins, swollen and distorted leaves, galls, russeting and ‘witches broom’, harden stems and leaf drop. Fruits develop red stippling leading to cracking, discolouration, blemishes, and uneven ripening. Symptoms are often confused with damage caused by growth regulators or herbicides.
Refer to the mite pest management plan for more information.