The disease myrtle rust has been found on Chatham Islands, where, unusually, it's expected to do more good than harm. Myrtle rust affects plants in the Myrtaceae family, including iconic New Zealand species such as pōhutukawa.
Experts believe there are no endemic plants of that species on the islands, and the myrtle rust is instead wrecking havoc on an unwanted weed.
Unitec School of Environment and Animal Science associate professor Peter de Lange spoke to Corin Dann.
