A total of 156 cases of myrtle rust have now been found in the Bay of Plenty.
The Ministry for Primary Industries released the figures to the Bay of Plenty Times yesterday, revealing most cases have been found in Te Puke (43), Bethlehem (29), Tauranga (17) and Rotorua (10).
A spokesman said Bay of Plenty was one of the worst affected areas in New Zealand and people needed to take care not to spread the tropical fungus and to check their local myrtle plants.
The Department of Conservation warned myrtle rust posed a threat to New Zealand's iconic Christmas tree, the pōhutukawa, because it was likely to be more active during warmer weather.
New Zealand's precious native myrtle plants including pōhutukawa, rātā, mānuka, kānuka and ramarama are vulnerable to the disease.