Myrtle rust (Puccinia psidii), a disease which affects plants in the family Myrtaceae, is recorded from over 440 species worldwide. Found established in Australia in 2010, and present in Hawaii, Japan, and southern China, there is concern that it will eventually reach New Zealand and cause damage to native Myrtaceae including pohutukawa, rata, kanuka, and manuka.

 

The disease damages foliage and shoots and in some cases flowers and fruit and on some species causes tip dieback but rarely kills mature plants. While its likely impact on New Zealand Myrtaceae is unknown, there is concern that it could affect regeneration.

 

The disease appears as a powdery bright yellow or orange/yellow pustules on actively growing leaves, shoots, flower buds and fruits of infected plants. Leaves may become buckled or twisted and die off.

 

This fungus is NOT present in New Zealand. If you suspect the presence of myrtle rust on plants in New Zealand, call MPI’s Exotic Pests and Diseases hotline on 0800 80 99 66. Read more on this Fact Sheet from the Ministry of Primary Industry.

Do not attempt to touch or collect samples as this may increase the spread of this disease.  You can read more about this on the Ministry of Primary Industry's website here.