Myrtle rust is an unwanted organism that has spread throughout the North Island, to parts of the South Island and Chatham Island.
Symptoms of myrtle rust are bright yellow-orange powdery pustules on young leaves, shoots, fruits and flowers of plants in the Myrtaceae family.
Myrtle rust cannot be eradicated from Aotearoa, but there are things you can do to help us track the spread and protect the ngahere/forest.
Myrtle rust attacks soft new growth including leaves, stems, buds, flowers and fruit.
Symptoms to look out for are:
Avoid contact with highly infected plants and do not collect samples as this might spread the disease.
If you identify myrtle rust on your property, find out what to do.
Make sure you wash your clothing, bag and shoes/boots when you get home.
To report a sighting of myrtle rust:
Your reports of myrtle rust are vital in helping understand where myrtle rust is in New Zealand, how far it has spread and what species it is infecting.
If you find myrtle rust on public conservation land, contact your local DOC office.
Myrtle rust affects New Zealand plants such as pōhutukawa, mānuka, rātā, swamp maire and ramarama. It affects exotic species including bottlebrush and lilly pilly. It also affects commercially grown species such as eucalyptus.
The conservation status of all native Myrtaceae was raised to ‘Threatened’ in 2018 after the arrival of myrtle rust.
Myrtle rust (Austropuccinia psidii) is also known as guava rust and eucalyptus rust.
Myrtle rust can:
Seedlings and young plants are especially vulnerable and severe and repeated infection can result in plant death.
Myrtle rust poses a major threat to New Zealand’s native biodiversity as it affects entire plant families including climbers, trees and shrubs. These plants provide essential ecosystem services. For example, pōhutukawa is a coloniser of bare coastal rock and is an important species for coastal stability.
Myrtle rust spores are microscopic and can easily spread across large distances by wind. Myrtle rust was probably carried by wind to New Zealand from Australia. Spores can also be transported on contaminated clothing, insects, rain splashes and equipment.
DOC has been working closely with the Ministry of Primary Industries to support research and initiatives that ensure Myrtaceae species remain for generations to come.
New Zealand has stringent biosecurity measures to protect against myrtle rust introduction. These include a complete ban on imports of cut flowers and foliage from myrtle species in New South Wales, Queensland and Victoria.
There are strict biosecurity procedures for DOC staff travelling between Raoul Island and the New Zealand mainland to prevent any people-assisted spread. Entry to the island is by permit only.
DOC put immediate restrictions on beehive movements on specific areas of conservation land in a bid to reduce the spread of myrtle rust. The decision was made after research from Plant and Food Research Ltd indicated bees may be a vector for the spread of myrtle rust.