Myrtle rust

What is Myrtle rust?

Myrtle rust (Puccinia psidii s.l.) is a newly described fungus that is closely related to the Eucalyptus/Guava rusts. These rusts are serious pathogens which affect plants belonging to the family Myrtaceae including Australian natives like bottle brush (Callistemon spp.), tea tree (Melaleuca spp.) and eucalypts (Eucalyptus spp.).

Myrtle rust is distinctive in that it produces masses of powdery bright yellow or orange-yellow spores on infected plant parts. It infects leaves of susceptible plants producing spore-filled lesions on young actively growing leaves, shoots, flower buds and fruits. Leaves may become buckled or twisted and may die as a result of infection. Sometimes these infected spots are surrounded by a purple ring. Older lesions may contain dark brown spores. Infection on highly susceptible plants may result in plant death.

Current situation

Reporting

Myrtle rust outbreaks should be reported to the land holder (e.g. local council, National Parks, Forests NSW etc). New hosts of Myrtle rust, and any detections in inland NSW should be reported to NSW DPI by sending photos to biosecurity@industry.nsw.gov.au 

Host list and distribution in NSW

There are over 100 known naturally susceptible host species and this number is expected to rise.

The distribution of Myrtle rust in NSW is shown by red and green zones.

Distribution maps

• Distribution of Myrtle rust by LGA in NSW as at January 1 2011 (1.2 Mb )
• Distribution of Myrtle rust by LGA in NSW as at January 1 2012 (2.6 Mb )

What can I do?

How you respond to Myrtle rust depends on where you live. If you live in Queensland, Victoria, Tasmania, South Australia, Western Australia, the ACT or the Northern Territory report any suspect detections to 1800 084 881. If you live in NSW report suspect detections to the land manager or if the detection occurs on new hosts or inland NSW ring 1800 084 881 or email good close up photos to biosecurity@dpi.nsw.gov.au

Options for treating Myrtle rust infected plants include:

• treatment with a registered fungicide according to the permit for chemical application (for example: for use in home gardens APVMA PER12828)
• replace diseased plants with non-susceptible plants (for example: plants not in the Myrtaceae group) 
• refer to the Resources page for relevant Factsheets

Resources and factsheets

Information is available on the resources page for home gardeners, bush regenerators, nursery and garden industry and the tea tree industry.

Further information

• NSW Office of Environment & Heritage Management Plan for Myrtle Rust on the National Parks Estate (www.environment.nsw.gov.au)
  
• Tea tree industry (www.attia.org.au)
• Nursery and garden industry (www.ngia.com.au)
• Australian native foods (www.anfil.org.au)
• New Rural Industries Australia (www.nria.org.au)
• AQIS (www.daff.gov.au)
• Victoria (www.dpi.vic.gov.au)
• Western Australia (www.agric.wa.gov.au) 
• Queensland (www.dpi.qld.gov.au) 
• Northern Territory (www.nt.gov.au) 
• Australasian Plant Pathology Society (www.appsnet.org)