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.
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.
(Some of the earlier timeline information was sourced from sciencelearn.org.nz)
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.
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 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 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.
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.
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.
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.
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.
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.
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.
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:
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.
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.
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.
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.
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.
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:
Science was critical input to achieving the strategy.
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.
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:
A University of Canterbury researcher was awarded an $800,000 fellowship to accelerate research into saving native trees from fungal pathogens, including myrtle rust.
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
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.
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.
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.
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.
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.
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.
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.
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.
A research paper was published summarising the diagnostic activities undertaken during the myrtle rust response in New Zealand.
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.
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.
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 is confirmed on the Chatham Islands in March 2022 by the Chatham Island Council Biosecurity Team.
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.
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.