Austropuccinia psidii (Myrtle Rust)

Help record the spread of the invasive myrtle rust and in doing so provide information on which species of Myrtatecae may it particuallry threaten, and if found in a new location provide for early management. This disease imported from South America is typified by the appearance of yellow spores on susceptible plants with symptoms appearing on young plant tissue such as leaves, stems, flowers, and fruit. Multiple infections can lead to severe defoliation and plant death. The spores produced by the pathogen, are easily spread to other plants through the wind or by human movement on clothes or transportation of infected material.

Myrtle rust (Austrouccinia psidii) is a fungal disease which infects plants in the Myrtaceae family. Common Australian Myrtaceae species include eucalyptus, willow myrtle, turpentine, bottlebrush, paperbark, tea tree and lilly pilly.

Since myrtle rust was first detected in NSW in April 2010 it has spread across the eastern Australian landscape in bushland reserves, home gardens, commercial operations and amenity settings such as parks and street plantings.

Myrtle rust can now be found on the eastern edge of New South Wales, Victoria, Queensland, Tasmania and on the Tiwi Islands in the Northern Territory.

When myrtle rust was first detected, a response was initiated to eradicate myrtle rust. The response was unsuccessful because myrtle rust spores are very easily dispersed by wind. In December 2010 eradication efforts were abandoned and transitioned to management.

Myrtle rust is a fungal disease which attacks soft, actively growing leaves, shoot tips and young stems. Severity of infection and symptoms vary with different host species. Myrtle rust may also attack flowers and fruit of certain hosts.

Generally myrtle rust starts as small purple spots on leaves. Bright yellow spores form in pustules within these purple spots. Pustules fade to dull yellow and then grey as the infection ages. In severe infections, spots enlarge and merge, often causing leaf distortion.

Heavy infection can result in the death of soft plant material. Whole plant death may occur in highly susceptible hosts.

https://invasives.org.au/our-work/pathogens/myrtle-rust/