Eucalyptus Rust: An Exotic Disease Threat to Australia
The fact sheet below has been prepared to raise awareness of eucalyptus rust, a disease exotic to Australia. Familiarise yourself with the contents of the fact sheet, particularly for signs of the disease and how to report any suspect symptoms you may find.
Eucalyptus rust (also known as guava rust) is part of the Puccinia psidii species complex, and is a potential threat to Australia's eucalypt plantations, commercial native forests and natural ecosystems.
What is it?
Eucalyptus rust is a fungal disease of plants belonging to the plant family Myrtaceae, and is exotic to Australia.
Eucalyptus rust is closely related to myrtle rust and both belong to the Puccinia psidii species complex. Myrtle rust has been introduced to Australia. It affects willow myrtle, turpentine, bottlebrush, paperbark, tea tree, lilly pilly and some species of Eucalyptus. Species of myrtle tend to be highly susceptible to myrtle rust.
Eucalyptus rust is considered to be one of the most serious threats to Australia’s eucalypt production forests and natural ecosystems, which predominantly consist of plants in the Myrtaceae family.
The Myrtaceae is a large family which includes eucalypts, paper barks (melaleucas), bottle brushes (callistemons), lilly pillies (syzygiums) and a range of other important Australian genera.
If eucalyptus rust became established in Australia, it could have a significant impact on eucalypt plantations, native forests and urban flora with indirect impacts on native fauna and human lifestyles.
Where is it?
The species complex of Puccinia psidii is established in Central America and the Caribbean, the United States including Florida and the Hawaiian Islands, South America, parts of Asia, South Africa and Oceania in New Caledonia. Myrtle rust has a restricted distribution in Australia. Eucalyptus rust is not known to be present in Australia.
Eucalyptus rust primarily attacks young (juvenile) leaves and also the flowers, shoots and fruits of a number of Myrtaceae species. First signs of rust infection are tiny raised spots or pustules on infected tissue. After a few days pustules turn a distinctive yellow colour.
Infected leaves become deformed and eventually shrivel. Severe infection can cause heavy defoliation and stunt growth. Recurrent infections can lead to death of trees or shrubs.
Eucalyptus rust spores are very small and can remain viable for months. The disease can spread from country to country through the movement of:
- infected plant material such as seeds, nursery stock and germplasm
- spores on timber, wood packaging and dunnage
- people carrying spores on clothing, shoes, equipment and other personal effects
- contaminated freight containers
- wind-borne spores.
Australia is undertaking a number of activities to prevent eucalyptus rust from entering and establishing in the country. These activities relate to:
- biosecurity measures and import conditions
- analysis of the pathways through which the rust could enter Australia
- surveillance for early detection of rust outbreaks
- industry biosecurity and response planning
- capacity building in Southeast Asia
- public awareness.
Technical experts agree that early detection of the rust before it enters Australia’s forests is the best way to maximise the chances of eradicating the disease should it reach the country.
Be vigilant for signs of rust and report suspect symptoms immediately by calling the national free call (except for calls from mobiles) hotline on telephone 1800 084 881.
Report suspect detections to your local department of agriculture or primary industries, call the
EXOTIC PLANT PEST HOTLINE
1800 084 881
For more information Plant Pest Hotline