Eriophyid Mites Affecting Ornamental Plants
Note Number: AG0180
Published: June 2000
Updated: February 2010
Eriophyid mites (Eriophyes spp.) are so small and difficult to see without some magnifying device that they often go undetected. They are wormlike and range in length from 0.1 to 0.3 mm. They also have considerable reduction in body structure; the two pairs of hind legs and most body setae have been lost and the front legs are reduced. The symptoms they produce include odd colour patches on leaf surfaces, leaf margins that roll inward or downward, swollen and distorted leaves, galls, russetting, and "witches brooms". The symptoms are often confused with the symptoms of
growth regulator or herbicide damage.
Camellia rust mite
In Victoria this mite causes brown, roughly circular patches or rings in the dark green of the upper surface of camellia leaves. The symptoms are similar to those caused by some viruses on other plants. The cast skins of the mites can often be seen as minute white specks on the backs of infested leaves. The upper surfaces of heavily infested leaves tend to curl down slightly and in severe infestations the under surface of the leaves turn a rusty brown colour. In warm weather the germination time is about two weeks.
Infestations that cause serious damage are rare in Victoria. The mite populations fluctuate markedly as a result of various environmental factors but if the mites cause appreciable damage spraying with a miticide may be warranted.
The eriophyid was found infecting carnations in Australia in the mid-late 1980s. The mites live between the leaf bases and stems and are numerous on the lower portions of the plants. The plants lose colour and may become distorted and stunted, with a greasy appearance.
Other eriophyid mites
Various native eriophyid mites occasionally cause "witches brooms" on eucalypts, leptospermums and other native plants. The leaves are drastically reduced and the shoots are bunched together to make a compact mass. Sometimes the leaf surfaces may show red markings where the mites have been feeding. Control measures are usually not required because often only a small proportion of the plant is affected and environmental factors appear to control the mite populations.
Contact/Services available from DPI
For effective pest and disease control, correct diagnosis is essential.
A commercial diagnostic service is available at DPI Knoxfield. For further information, contact the Diagnostic Service. ph: (03) 9210-9222 or fax (03) 9800 3521
Contact the Customer Service Centre of the Department of Primary Industries, Victoria at 136 186
For information relating to the safe and appropriate use of chemicals, including management of chemical residues and licensing requirements, call the DPI Customer Service Centre of 138 186 and ask to speak to your local chemical standards officer or visit www.dpi.vic.gov.au/chemicalstandards.
This Agnote was developed by David Williams, Bioscience Research, Victoria, June 2000.
It was reviewed by Harold Adem, Farm Services Victoria, February 2010.
Published and Authorised by:
Department of Environment and Primary Industries
1 Spring Street
This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968.
The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication