History of myrtle rust in Aotearoa New Zealand

Myrtle rust is widely distributed across the North Island and in the north and west of the South Island. This timeline tracks its spread across the country, and efforts to manage the disease and safeguard New Zealand’s myrtles.

History of myrtle rust in Aotearoa New Zealand

 

Myrtle rust around the world

Myrtle rust global distribution map (Source: CABI)

 

Native to South America, Myrtle rust has rapidly spread around the world in the last 40 years and is established as an invasive pest in many countries, including South Africa, China, Indonesia, Hawaii, New Caledonia.

Summary of Myrtle Rust Invasiveness – CABI Digital Library

(Some of the earlier timeline information was sourced from sciencelearn.org.nz)

Myrtle rust reaches Australia in 2010

Myrtle rust was first detected in Australia in 2010. Initially the Australian Government tried to contain the disease, but it quickly spread and became established along Australia’s east coast and then other parts of the country.

What did New Zealand do?

Biosecurity officials implemented a range of measures in case the disease spread to New Zealand. Imports of flowers and foliage from Australian Myrtaceae family plants were banned.

Myrtle rust found on offshore Raoul

Raoul Island Canopy, 2017. 

March 2017 

Myrtle rust was detected on Kermadec pōhutukawa trees on subtropical Raoul Island, part of the Kermadec Island chain. Department of Conservation (DOC) scientists made several visits to the island between March 2017 and March 2018 to set up monitoring of myrtle .

Myrtle rust detected on New Zealand mainland

May 2017 

Myrtle rust was first found on New Zealand’s mainland, in a Kerikeri plant nursery. Soon after several sites in the Taranaki region had confirmation of myrtle rust in commercial and private properties.

Incursion response

MPI and DOC, with the help of local iwi, the nursery industry, and local authorities implemented an intensive operation to determine the spread and attempt to contain and control further spread of myrtle rust.

Myrtle rust response surveillance in Kaipara

Restrictions on plant movement

MPI immediately put restricted place notices in effect for any properties with myrtle rust. A Controlled Area Notice was imposed in Taranaki preventing movement of plant material. The nursery industry adopts protocols to try and prevent the spread.

Urgent research needed

June to July 2017 

Establishment of the Myrtle Rust Strategic Science Advisory Group

MPI established the Myrtle Rust Strategic Science Advisory Group (SSAG). Members included expert scientists, iwi and government representatives. The SSAG’s first task was to identify and prioritise immediate research needs to help combat its spread.

Urgent research into the threat of myrtle rust

Cabinet provided MPI $3.7 million over two years for urgent research into the myrtle rust threat to New Zealand. MPI commissioned research projects based on priorities set by the SSAG to be completed mid-2019.

Catalyst Strategic Fund

The Ministry of Business, Innovation & Employment’s (MBIE) Catalyst Strategic Fund provided $1.5 million towards a collaborative project to address myrtle rust’s threat to New Zealand.

Catalyst Strategic Fund - Ministry of Business, Innovation & Employment

Myrtle rust spreads throughout New Zealand mainland

May 2017 to March 2018 

Myrtle rust continued to be detected in new regions across the North Island, including the Auckland, Bay of Plenty, Waikato, Tairawhiti, Manawatū and Wellington. By April 2018, Myrtle rust was first detected in the Tasman region of the South Island.  

Shift in approach

April to May 2018

After 11 months of intensive response activity, it was determined it was not feasible to contain the disease. The management approach changed to long-term management of myrtle rust, with the main focus to:

  • Continue urgent research to investigate and test possible treatments for myrtle rust, boost resistance, and develop techniques for long-term storage of native myrtle germplasm.
  • Collect native myrtle seed for long-term storage (seed-banking).
  • Targeted surveillance of high-risk sites where myrtle rust has not been detected.

Focus on science and research 

Syzygium maire in vitro. Photo credit: Karin van der Walt, Otari Native Bush

September to December 2018

Beyond Myrtle Rust

MBIE provided $13 million over 5 years to Manaaki Whenua – Landcare Research’s Beyond Myrtle Rust collaborative research programme into the behaviour, ecology and impacts of the disease in New Zealand. The programme had four interlinking research areas: pathogen dynamics; ecosystem impacts; novel mitigation techniques; kaitiakitanga and Māori-led solutions.

Biological Heritage National Science Challenge

The Government provided a further $5 million over three years to the Biological Heritage National Science Challenge (Ngā Rākau Taketake) for research to combat the spread of myrtle rust which builds on aspects of MPI- funded research.

Surge funding for kauri dieback and myrtle rust research - The Beehive

Biological Heritage National Science Challenge

MPI funded research

First Myrtle Rust Symposium

In mid-December, the first and Workshop was held in Wellington, organised by the Myrtle Rust Strategic Science Advisory Group. Stakeholders shared the current state of knowledge of myrtle rust science and identified research priorities for a Myrtle Rust Science Plan.

Download Myrtle Rust Science Plan [PDF, 1,202KB]

Working together to safeguard myrtles 

May 2019 

Myrtle rust was confirmed in Greymouth, the first time on the West Coast of the South Island. By the end of June 2019, nationally, over 1000 infected sites were confirmed.

MPI’s formal recording of infected sites in areas known to be infected was discontinued. The focus shifts to supporting property managers, councils, iwi, central government, and researchers to use science to better understand the disease and learn how to help manage its impact and safeguard New Zealand’s myrtles.

The public is encouraged to report myrtle rust findings via the iNaturalist website (a crowdsourced website), where experts can check to confirm the plant species and whether the symptoms are consistent with myrtle rust.

Myrtle Rust Reporter - iNaturalist website

How to report myrtle rust

Myrtle Rust Strategy and Science Plan

July 2019

The Myrtle Rust Strategic Science Advisory Group released the Myrtle Rust Science Plan which was developed in consultation with more than 50 researchers, stakeholders and Māori. The Science Plan provides a guide to what science will be most valuable for the management of myrtle rust.

Download Myrtle Rust Science Plan [PDF, 1,202KB]

The New Zealand Myrtle Rust Strategy 2019-2023 was released by the Myrtle Rust Governance Group. The Strategy provides a framework to guide a collective and collaborative approach to dealing with myrtle rust up until 2023. The Strategy was prepared by Biosecurity New Zealand following a series of workshops with key partners, including Māori and a range of stakeholders.

The Strategy focused on:

  • growing knowledge of myrtle rust behaviour and impacts;
  • identifying options for its future management and minimising impacts;
  • identifying ways to conserve genetic material of myrtle species; and
  • supporting tāngata whenua, partners and stakeholders as they make decisions about their plants and the places that are important to them that may be affected by myrtle rust.

Science was critical input to achieving the strategy.

New Zealand Myrtle Rust Strategy 2019-2023

Second Myrtle Rust Symposium

September 2019

The second Myrtle Rust Science Symposium was held in Auckland, attracting almost 100 stakeholders, including researchers, iwi, councils, funders, honey and plant industry representatives and academics. Delegates discussed the latest research findings, management tools and approaches and share insights, learnings, and new initiatives.

Myrtle Rust Science Symposium - MPI Media Release

Myrtle Rust Stakeholder Group

October 2019

The Myrtle Rust Governance Group agrees to disband after completion of the Myrtle Rust Strategy.

The group was replaced by a new Myrtle Rust Stakeholder Group whose purpose is to:

  • support and encourage the sharing of knowledge and information between scientists, practitioners, organisations, communities, and individuals
  • ensure consistent messages are shared around the current situation, impacts and what to do about myrtle rust.
  • provide a platform for organisations to raise issues and consider actions.

Further Research Funding

October 2019

A University of Canterbury researcher was awarded an $800,000 fellowship to accelerate research into saving native trees from fungal pathogens, including myrtle rust. 

UC Researcher awarded 2019 Rutherford Discovery Fellowship – Canterbury University

Myrtle Rust Community Group

November 2019

Ngā Rākau Taketake, restarted the Myrtle Rust Community group, bringing together community groups, science/research organisations, local councils, and government agencies to stay well connected and have access to the same information.

Organisations interested in joining the community group can contact NRTsupport@bioheritage.nz

Third myrtle rust symposium

Beyond Myrtle Rust, a $13 million research programme managed by Manaaki Whenua – Landcare Research, sponsored a myrtle rust symposium at the 2020 New Zealand Ecological Society Conference in Christchurch with presenters sharing myrtle rust research updates. 

Beyond Myrtle Rust – Manaaki Whenua

Monitoring and Surveillance

January 2020

A form to monitor the long-term symptoms and impacts of myrtle rust on specific host trees in New Zealand was published on the myrtle rust website. The form is for use by groups who have some level of knowledge of myrtle rust symptoms.

Download the New Zealand Myrtle Rust Monitoring Form [Word, 13.6MB]

A surveillance map of myrtle rust was made available on the myrtle rust website. It contains records of both uninfected host plants as well as the latest known distribution of the disease in New Zealand. The map combines datasets from Biosecurity New Zealand, iNaturalist, the Department of Conservation, Plant and Food Research, and Botanic Gardens. 

Myrtle Rust Surveillance Map - Plant and Food Research

Ngā Koiora Tuku Iho (part of NZ’s Biological Heritage Challenge), developed and published a myrtle rust science stocktake with assistance from the Department of Conservation and Ministry for Primary Industries.

Myrtle Rust Science Stocktake - Ngā Koiora Tuku Iho

Initial research findings

December 2019 to July 2020

Impacts of myrtle rust in New Zealand

A New Zealand Garden Journal article provides a summary of the impact of myrtle rust in New Zealand since its arrival in 2017 to 2019.

Download Impacts of myrtle rust in New Zealand - Plant and Food Research [PDF, 8.4MB]

Myrtle rust sexually reproducing  

New evidence that the fungus that causes myrtle rust is reproducing sexually in New Zealand in addition to cloning itself. This means the fungus is likely to have a better chance of adapting to natural plant resistance as well as biological and chemical controls.

Download Myrtle rust is having sex - Ngā Koiora Tuku Iho [PDF, 485KB]

Largest fungal genome assembled

A trans-Tasman research collaboration successfully completed the assembly of a nearly complete genome for the fungus that causes myrtle rust. The Austropuccinia psidii genome is the largest fungal genome assembled to date.

Researchers successfully assemble myrtle rust genome

Fungicide effectiveness

Laboratory testing of fungicide effectiveness against myrtle rust was conducted on two susceptible New Zealand native myrtles; the garden hybrid Lophomyrtus ‘Magic Dragon’ and pōhutukawa. Overall, the findings showed those fungicides that included a demethylation inhibitor and strobilurin were most effective. 

Testing the effectiveness of fungicides against myrtle rust

Myrtle rust diagnostics

A research paper was published summarising the diagnostic activities undertaken during the myrtle rust response in New Zealand.

Chasing myrtle rust in New Zealand

Ex situ conservation strategies for endangered native myrtles

A study highlights the importance of holistic conservation strategies to safeguard the germplasm of native New Zealand myrtles. It includes successful in vitro culture for several myrtle species, and hand pollination of Bartlett’s rātā, New Zealand’s rarest tree species. The research describes three methods (conventional seed banking, cryopreservation, and in vitro culture) which can be used to store germplasm (seed, embryos, pollen, shoots or cells) of native New Zealand myrtles.

Download Research highlights ex situ conservation strategies for endangered native myrtles [PDF, 164KB]

Monitoring myrtle rust on native forests

The first monitoring study of myrtle rust in New Zealand native forests focused on two endemic species, ramarama and rōhutu; both are considered highly susceptible to the disease.

Download Monitoring myrtle rust on native forests [PDF, 87.6KB]

Myrtle rust found in Christchurch

June 2021

Myrtle rust is reported on a mature hedge of the Lophomyrtus cultivar on iNaturalist. The find marks a new southern point for the likely establishment of the disease. Previous sightings in Christchurch have been on plants purchased in nurseries in other regions and relocated to Christchurch.

Myrtle rust find reported in Christchurch – Manaaki Whenua Landcare Research

Myrtle rust found on the Chatham Islands

March 2022

Myrtle rust is confirmed on the Chatham Islands in March 2022 by the Chatham Island Council Biosecurity Team.

Myrtle rust on the Chatham Islands – Chatman Islands Council

Myrtle rust found on the Chatham Islands – Manaaki Whenua Landcare Research

Inaugural Australasian Myrtle Rust Conference

June 2023

With a focus on building connections, the inaugural Australasian Myrtle Rust Conference was held in Sydney, bringing together researchers and biosecurity practitioners to share insights and findings from local and international research projects. Videos of the conference presentations are available on YouTube. 

Inaugural Australasian Myrtle Rust Conference – Manaaki Whenua

Myrtle Rust Conference 2023 presentations – YouTube

The future focus

There continues to be a strong focus on science to find ways to manage and slow the spread of the disease. Everyone from researchers to the groups managing myrtle rust on the ground are encouraged to work together to help safeguard and sustain our native myrtles. Stakeholders continue to work collaboratively to determine the next phase of myrtle rust efforts.

Public observations continue to be recorded through iNaturalist, supporting researchers to understand the spread.

Myrtle Rust Reporter - iNaturalist website

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