As we move into Spring, Waikato residents are asked to be on the lookout for myrtle rust as the disease comes out of a dormant patch.

Two cases of myrtle rust were confirmed yesterday on mature trees in Otorohanga, pushing the national number of confirmed cases to 118.

Ministry of Primary Industries Response Manager Doctor Catherine Duthie says the majority of discoveries have been in the Taranaki and in residents gardens.

"And so for that reason we'd really like members of the public to keep an eye out on the trees in their gardens and in their surrounding environments for Myrtle Rust."

She says the latest discovery of myrtle rust is disappointed but not unexpected.

Dr Duthie says the disease has been relatively dormant over the winter months but more humid weather could bring them out.

"We should to see some of these infections which may have been dormant over the winter months, they should start sporulating and you'll see the classic yellow spores on the plants."