Myrtle rust isn’t news anymore. It’s been in Australia since 2010, and eradication was declared impossible within the first year. But that doesn’t mean we’ve stopped caring about where it spreads or what impact it’s having.

The 2025 data shows some interesting patterns—and a few concerning developments.

Where Things Stand

As of December 2025, myrtle rust is established throughout coastal and near-coastal areas of Queensland, New South Wales, and Victoria. It’s present in parts of South Australia, though distribution is more scattered there. Western Australia and Tasmania remain officially rust-free, though both states are under constant surveillance pressure.

The fungus (Austropuccinia psidii, formerly Puccinia psidii) infects plants in the Myrtaceae family, which includes eucalypts, paperbarks, bottlebrushes, tea trees, and many other Australian native species. Some species are devastated by infection; others are barely affected.

This variability makes management complex. You can’t treat myrtle rust as a single uniform problem—it’s hundreds of different problems depending on which plant species and ecosystems are involved.

2025 Range Extensions

The most significant 2025 development is continued southward spread in Victoria. New detections this year include populations in Wilson’s Promontory National Park, previously thought to be too cool and exposed for rust establishment.

If myrtle rust can survive at Wilson’s Prom, there aren’t many Victorian locations where it can’t establish. That has implications for Tasmania, which has similar climates in coastal areas.

In Queensland, spread into higher elevation rainforests continues. Detections this year in areas above 800m altitude in the Scenic Rim region suggest the fungus is adapting or that suitable microclimates exist at higher elevations than initially expected.

South Australia saw new detections in the Adelaide Hills and Fleurieu Peninsula. These aren’t surprising geographically—they’re extensions of already-established populations—but they confirm ongoing spread despite containment efforts.

Western Australia’s Defensive Position

WA remains the big question mark. The state has invested heavily in border surveillance, rapid response to detections, and public awareness campaigns. So far, it’s worked—there are no established populations.

But there have been detections. Nursery surveillance has caught infected plants multiple times, most recently in August 2025 at a Perth nursery that had received stock from interstate. The infected plants were destroyed, surrounding plants were treated with fungicide, and monitoring continues.

Each detection is a near-miss. The fact that WA has avoided establishment so far is partly good management and partly luck. One infected plant escaping detection in a botanical garden or private collection could be enough to seed a self-sustaining population.

The economic stakes are high. WA’s eucalyptus oil industry, wildflower industry, and native plant nursery sector are all vulnerable. Establishment would also threaten conservation values in the Southwest Australian Floristic Region, a global biodiversity hotspot.

Species-Specific Impacts

Some plant species face severe threats. Rhodomyrtus psidioides (native guava) is nearly wiped out across its Queensland range. Rhodamnia rubescens (scrub turpentine) is critically endangered, with rust contributing to ongoing decline.

Several Syzygium species (lillypillies) are heavily impacted. Coastal populations of Syzygium moorei show consistent severe infection. Regeneration is compromised—seedlings and young plants are killed, preventing population replacement.

On the other hand, many eucalyptus species are lightly affected or unaffected. Eucalyptus pilularis (blackbutt) occasionally shows minor leaf infections but with no significant impact. Eucalyptus grandis (flooded gum) is similarly tolerant.

Melaleuca species (paperbarks) show mixed responses. Melaleuca quinquenervia (broad-leaved paperbark) in northern NSW and Queensland is heavily impacted in some locations, nearly symptom-free in others. The reason for this variation isn’t clear—possibly different rust strains, genetic variation in the trees, or environmental factors.

Surveillance and Monitoring

National surveillance coordination has improved significantly since the early chaotic years. The National Myrtle Rust Transition to Management program coordinates data collection across states and territories.

Real-time reporting through digital platforms allows rapid sharing of detection information. Some land managers now use automated image recognition systems to flag potential rust symptoms in field photos, though human confirmation is still required. Technology firms like AI automation services have been working with environmental agencies to improve these detection systems and integrate surveillance data across different platforms.

Citizen science contributes substantially. Bushwalkers, naturalists, and community groups report suspected infections through apps and web portals. The quality of reports has improved as people learn what to look for. Not every report pans out, but enough do that it’s a valuable data source.

Fungicide Use in Conservation

Fungicide application remains the only practical tool for protecting high-value conservation populations. Phosphorous acid (phosphite) provides some protection when applied preventively, but it requires repeated application and doesn’t work equally well for all species.

Royal Botanic Gardens across Australia continue protective spraying programs for rare species in their collections. This prevents ex-situ collections from being lost, though it’s an ongoing expense.

In-situ treatment of wild populations is more difficult. Access constraints, large areas, and the need for repeated applications make it impractical except for very small, highly valuable populations.

Private landowners are increasingly using fungicides on high-value ornamental plantings—especially lillypillies used in hedges and screens. This is probably the largest fungicide application by volume, though data on private use is limited.

Resistance and Adaptation

The big question is whether susceptible plant species will develop resistance. There’s some evidence of this happening.

In heavily infected areas, you sometimes find individual plants that remain healthy despite being surrounded by infected, dying plants. These could be naturally resistant individuals. If their resistance is genetic and heritable, those plants become important for recovery.

Several research projects are collecting seed from apparently resistant individuals and testing their offspring. If resistance is confirmed and stable, those genetics can be used for restoration plantings and potentially breeding programs.

There’s also evidence of reduced impact over time in some locations. Areas that saw severe damage in 2011-2013 now show lighter infection levels and better plant survival. This could be resistant plants surviving while susceptible ones died, or it could be some form of environmental or pathogen change. The mechanisms aren’t fully understood.

Climate Change Interactions

Climate change will likely expand suitable habitat for myrtle rust. Warmer winters mean the fungus can survive in areas currently too cold for year-round presence.

However, changes in rainfall patterns complicate predictions. The fungus requires moisture for spore germination and infection. If some areas become drier, rust pressure might decrease even as temperatures warm.

Extreme weather events probably favor the rust. Heavy rainfall after dry periods creates ideal infection conditions. More frequent extreme weather could mean more severe infection even if average conditions don’t change much.

Management Realities

The transition from “eradication” mindset to “management” mindset took several years and was painful for many conservationists. Accepting that we’re living with myrtle rust permanently felt like defeat.

But acceptance enables more practical approaches. Instead of trying to eliminate the rust—impossible with current technology—effort focuses on protecting the most vulnerable species, slowing spread to uninfected areas, and supporting research into resistance and adaptation.

This isn’t giving up. It’s recognizing that resources are limited and should be directed where they’ll be most effective.

2026 Priorities

Looking ahead, several priorities are clear. First, maintaining WA and Tasmania rust-free status as long as possible. Every year without establishment is valuable.

Second, intensifying protection for critically endangered species where rust is a contributing threat. These are often small populations where targeted intervention is feasible.

Third, expanding resistance research and beginning to incorporate resistant genetics into restoration programs.

Fourth, improving prediction of where rust will spread next. Better models would allow pre-emptive monitoring and rapid response.

A Sobering Perspective

Myrtle rust is what an uncontrolled pest looks like. Despite massive investment in detection and response, it spread across the entire east coast in under a decade. We slowed it but didn’t stop it.

This experience informs how we think about future biosecurity threats. Early detection matters enormously. Rapid response can make the difference between containment and failure. But even with good systems, some invasions succeed.

The best approach remains preventing entry in the first place. Once a pest like myrtle rust establishes, your options narrow dramatically. We’re managing consequences now, not solving the problem.

That’s a lesson worth remembering as we face new threats—and there will always be new threats.