Disappointment as myrtle rust spreads to Mangawhai

 

Confirmation of new myrtle rust discoveries in the Kerikeri and Mangawhai areas has prompted a plea from biosecurity officials for Northlanders to continue to report any suspected cases of the serious fungal plant disease.

The latest Northland discoveries come just a month after the Ministry for Primary Industries (MPI) and Department of Conservation (DOC) announced that – given the prevalence of the rust across susceptible parts of New Zealand – the fight against it was ‘changing gear’.

Announcing the changed approach, MPI spokesperson Dr Catherine Duthie said the windborne nature of the disease meant despite an enormous national operational effort over the past year (that had seen more than 95,000 plants inspected and several thousand destroyed) containing the rust hadn’t proved possible.

“We (MPI) have signalled for a while the likely need to change gear from intensive surveillance and the removal and destruction of host plants to one where we look to manage the disease over the long term," she said.

The Northland Regional Council (NRC) says over the past few days tests had confirmed the presence of myrtle rust at several new sites in Kerikeri (one of the first mainland areas in New Zealand affected by the disease last year) and at Mangawhai.

Kane McElrea, NRC Biosecurity Manager Partnerships & Strategy, says the rust affects plants in the myrtle family, which includes iconic species like pohutukawa, manuka and rata. It’s also commonly found on ramarama, also known as bubble leaf.

With more than 50 infected trees over 20 sites covering six square kilometres in Kerikeri alone, news the rust had now reached other parts of Northland was disappointing, but not unexpected given the ease with which it could spread.

Mr McElrea says although the primary responsibility for managing myrtle rust remains with MPI, the regional council is still keen to work with the Ministry and the wider community wherever practically possible.

Mr McElrea encourages Northlanders to check their properties for signs of the rust but stresses if they do discover what they think are myrtle rust symptoms, it’s extremely important not to touch the suspicious plant.

“Myrtle rust spores are microscopic and can be easily spread across large distances by wind, or via insects, birds, people, or machinery so instead of touching a suspicious plant, call the MPI hotline immediately. If you have a camera or phone camera, take clear photos, including the whole plant, the whole affected leaf, and a close-up of the spores or affected area of the plant.”

Meanwhile, Dr Duthie says going forward, the national focus would have to be on a science programme designed to lift understanding around the disease, such as ways to treat myrtle rust, resistance and susceptibility, and to improve seed banking collection.

A second key focus would be working with communities to support regional efforts to combat myrtle rust, which could include regional surveillance programmes, identification and protection strategies for taonga plants and special locations, advice to landowners, seed banking and broad community engagement.

Dr Duthie says during the shift to long-term management, MPI and the Department of Conservation (DOC) would be engaging with iwi and hapu, territorial authorities, the plant and nursery industries and communities to support the development of regional programmes.

As part of involving and informing communities at the grassroots, MPI and DOC will hold hui with iwi and councils in affected regions, including Northland, over the coming months.

The Department of Conservation would also continue to focus on seed collection to secure the long-term future of native myrtle plants and monitoring biodiversity impacts to inform science and management actions.

Dr Duthie says DOC will also continue efforts to protect sites of high ecological and cultural significance.

 Information about myrtle rust is available from the MPI website mpi.govt.nz. Northlanders are encouraged to report any possible myrtle rust cases to MPI’s Exotic Pest and Disease Hotline 0800 809 966.


Members of a multi-agency biosecurity response team checking for signs of myrtle rust soon after its discovery in Kerikeri last year.