Myrtle rust is a serious fungal disease of plants. Although it is not present on the New Zealand mainland it has recently been detected on Raoul Island. This fungus has a wide host range within the Myrtaceae, a family of plants that include many of New Zealand’s most iconic trees, e.g., pōhutukawa, rata, manuka, kanuka and important introduced species like Eucalyptus and one of our favourite autumn fruits, the feijoa.
Myrtle rust often attacks fresh new growth and early infestations are characterised by yellow powdery eruptions on the surface of leaves as well as flowers, fruits, buds, and shoots. The spores themselves are microscopic so you won’t see them. However, don’t touch the yellow powder as you will coat yourself and your clothes in spores — potentially spreading the disease further. Further information can be found in this MPI fact sheet.
What should you do if you see something suspicious?
Help protect New Zealand, get out there and keep looking.
Thanks from the NatureWatch NZ Team