Myrtle rust (Austropuccinia psidii)

What is myrtle rust?

Myrtle rust is a disease caused by the exotic fungus Austropuccinia psidii (formerly Puccinia psidii, initially identified as Uredo rangelii). Overseas there are known to be several strains of P. psidii. At this stage Australia has only one strain.

Myrtle rust threatens trees and shrubs in the Myrtaceae family of plants which includes Australian natives like bottle brush (Callistemon spp.), tea tree (Melaleuca spp.) and eucalypts (Eucalyptus spp., Angophora spp., and Corymbia spp.). The disease can cause deformed leaves, heavy defoliation of branches, reduced fertility, dieback, stunted growth, and plant death.

It is not known how myrtle rust entered Australia. Myrtle rust spores can be spread easily via contaminated clothing, hair, skin and personal items, infected plant material, equipment as well as by insect/animal movement and wind dispersal. These characteristics make it extremely difficult to control and impossible to eradicate from natural settings.

A fungicide spray program can effectively reduce the levels of myrtle rust infection in plant nurseries and home gardens. However, this is not feasible for natural bushland settings where it is critical to minimise the risk of its introduction or spread on items such as clothing, equipment, vehicles, machinery or plant material.

Where has myrtle rust been found?

Myrtle rust was first detected in Australia in 2010 on the NSW central coast. It has since spread rapidly. It is established along the east coast of Australia from southern NSW to far north Queensland with impacts recorded across a range of ecosystems. It is also present in Victoria, mainly at production nurseries and wholesale outlets in and around metropolitan Melbourne. The first detection of myrtle rust in Tasmania was in February 2015 at a property near Burnie on the north-west coast. It has since been found in the north and north-west of Tasmania in private gardens and plant nurseries, but has not been recorded in native ecosystems. In May 2015 it was detected on Melville Island in the Northern Territory and has since been found in the Darwin region. As of April 2016, about 350 native species have proved susceptible to myrtle rust. For further information on the known distribution of myrtle rust within these states, please refer to the websites below:

Emergency response to myrtle rust

In 2010 after myrtle rust was detected, Australian Government, state and territory government agencies worked with industry groups and the owners of infected properties in an attempt to suppress the outbreak and eradicate the disease. The emergency response to myrtle rust included:

  • removal of host material at infected properties
  • establishment of a buffer zone around infected properties and fungicide treatment in these areas
  • application of fungicide to continue suppression of the disease
  • spore trapping to establish whether the rust was spreading
  • quarantine controls on infected properties to prevent further movement of infected plants
  • general surveillance
  • host range testing.

The eradication effort was unsuccessful - with the disease spreading from commercial properties into native bushland and on to other areas.

In December 2010, the heads of Australian Government and state agencies responsible for biosecurity took the decision, based on expert technical advice, that it was not technically feasible to eradicate myrtle rust from Australia. The Australian Government funded a program to enable the transition from eradication to management of myrtle rust as it became naturalised across Australia.

Consideration by the Threatened Species Scientific Committee

In 2014-2015, the Threatened Species Scientific Committee considered a public nomination to list ‘exotic rust fungi of the order Pucciniales that are pathogenic on plants of the family Myrtaceae’ as a Key Threatening Process under the Environment Protection and Biodiversity Conservation Act 1999.

The Committee decided that such pathogens are encompassed within the existing ‘Novel biota and their impact on biodiversity’ Key Threatening Process. The nomination and more information on the Committee’s consideration are available here: Key threatening process nominations not prioritised for assessment.

Myrtle Rust Workshop, Canberra, December 2012

On 12 December 2012 the Department held a national workshop in Canberra to facilitate communication and collaboration on management actions and research into myrtle rust in natural ecosystems. Representatives from all states and territories and the research community were in attendance.

December 2014 National teleconference

In December 2014, the Department hosted a national teleconference of expert researchers, state and territory government representatives and non-government organisations to share information about the distribution of myrtle rust and its impact on species and communities; and identify critical management and research actions to manage the impact of myrtle rust in our natural ecosystems.

National Environmental Science Programme 2016

In 2016, the Threatened Species Recovery Hub of the National Environmental Science Programme will undertake a project to demonstrate the impacts of myrtle rust on species and plant communities and determine a national method of assessment and monitoring. Information about this project will be made available on this website.

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