Curtin University PSHB Study: Large Parts of Australia Vulnerable to Tree-Killing Beetle

Understanding the Polyphagous Shot-Hole Borer Threat 78 77

The polyphagous shot-hole borer (PSHB), scientifically known as Euwallacea fornicatus, is a diminutive ambrosia beetle originating from Southeast Asia. Measuring just 2 millimeters in length, this invasive pest poses a massive threat to trees worldwide by boring into trunks and branches while cultivating a symbiotic fungus, Fusarium euwallacea. This fungus clogs the tree's vascular system, starving it of water and nutrients, often leading to branch dieback or complete tree death. The process begins when female beetles excavate galleries within the wood, laying eggs and farming the fungus as food for their larvae. Adult emergence follows, perpetuating the cycle.

In Australia, PSHB first appeared in Perth's metropolitan area in 2021, likely arriving via infested wood packaging or nursery stock. Since then, it has infested thousands of trees, prompting widespread removal efforts. Over 4,960 trees have been felled in Perth alone, with many more pruned to halt spread. 96 The beetle targets more than 500 host species, including economically vital horticultural crops like avocados, citrus, mangoes, and pears, as well as urban favorites such as Moreton Bay figs, coral trees, and native species like marri and jarrah.

This invasive species exemplifies broader biosecurity challenges, where global trade inadvertently introduces pests. Curtin University's recent research underscores the urgency, modeling PSHB's potential spread and highlighting vulnerabilities across the continent.

Curtin University's Groundbreaking Research Publication

Published in the Journal of Biogeography on January 8, 2026, the paper titled "Boring Beetles and Super Models: Mapping Potential Distributions of a New Invader" represents a milestone in invasive species modeling. 101 Lead author Dr. Andrew Coates, from Curtin’s School of Molecular and Life Sciences, alongside co-author Professor Ben Phillips—a WA Premier’s Science Fellow—developed the most detailed mechanistic model for PSHB to date.

The study utilized high-resolution daily climate data, vegetation maps, and synthesized biological parameters from global observations. Leveraging the Pawsey Supercomputing infrastructure, researchers simulated the beetle's full life cycle, including egg-to-adult development, fungal symbiosis, and dispersal. Key innovations include temperature-dependent stage-structured population dynamics, estimating growth rates inside host trees and predicting outbreak hotspots temporally and spatially.

The Population Biology and Genomics Group at Curtin exemplifies how university research drives national biosecurity. Such work opens doors for PhD candidates and research assistants in population modeling and genomics, with opportunities in similar projects on cane toads or red foxes.Explore research jobs in these fields at Australian universities.

Key Findings: Vast Swathes of Australia at Risk

Curtin's model reveals that PSHB thrives in diverse Australian climates, with enormous invasion potential. Current Perth infestations occupy only marginally suitable areas; highly suitable zones remain uninvaded, particularly on the east coast. Queensland and New South Wales emerge as highest-risk states, where ideal temperatures could fuel explosive population growth—doubling every 14 days under optimal conditions. 99

• High suitability: Coastal QLD (Brisbane, Gold Coast), NSW (Sydney, Newcastle), parts of VIC and SA.
• Medium risk: Inland farming regions, urban centers like Melbourne and Adelaide.
• Lower but notable: Tasmania peripheries, northern WA beyond Perth.

Without human-mediated transport, natural spread caps at 3-3.75 km per year via short flights. However, infested firewood, mulch, or green waste accelerates this dramatically. Summer peaks beetle abundance, amplifying detection challenges.Curtin media release

Current Situation in Western Australia: From Eradication to Management

Perth's experience serves as a stark warning. Detected in 2021, PSHB prompted a $57 million national eradication effort, felling nearly 5,000 trees across 135,000 inspected properties. 76 Iconic sites like Kings Park lost 42 Moreton Bay figs. By June 2025, the National Management Group deemed eradication unfeasible, shifting to a "Transition to Management" plan with quarantine zones restricting wood movement.

Western Australia's Department of Primary Industries and Regional Development (DPIRD) now invests over $2 million in university-led research, including Curtin's modeling. Multi-agency responses involve chipping prunings smaller than 2.5 cm to kill beetles, alongside chemical trials and biological controls. Economic tolls mount: invasive pests cost Australia $40 billion annually, doubling every six years.

Local governments like City of Perth committed $1 million, replacing removed trees at a 3:1 ratio to preserve canopy cover.

Photo by MARIOLA GROBELSKA on Unsplash

Implications for Urban Landscapes and Agriculture

Urban trees provide cooling, biodiversity, and aesthetic value; PSHB threatens these benefits nationwide. Sydney's native figs, Brisbane's poincianas, and Melbourne's London planes face decimation, potentially costing millions in replacements and exacerbating urban heat islands.

Agriculturally, horticulture bears the brunt. Avocado orchards in QLD/NSW, citrus groves, and mango plantations risk severe losses, mirroring California's billions in damages. Bushland natives like eucalypts could suffer secondary invasions, disrupting ecosystems.

Stakeholder perspectives vary: growers urge stricter quarantines, councils prioritize canopy rehab, while researchers advocate predictive tools. Curtin's model informs these, enabling targeted surveillance.

Innovative Tools from Curtin Research

Complementing the publication, Dr. Coates developed the PSHB Survey Planner app (try it here). Users select locations on an interactive map; the app simulates annual population dynamics using 10-year climate averages, highlighting optimal survey weeks (e.g., summer highs) via calendars. This prioritizes limited resources for traps or inspections, boosting early detection odds.

Source code on GitHub empowers researchers to customize. Such digital tools exemplify translational research from universities, aiding biosecurity agencies.

National and Global Context

Australia's PSHB saga echoes global invasions: California lost millions of trees since 2003, prompting $multi-billion responses. South Africa, Israel, and South America report similar woes. Curtin's model, validated there, predicts hotspots universally.

Nationally, a taskforce drafts management plans, emphasizing data-sharing among unis, governments, and industry. WA's pivot highlights needs for rapid R&D partnerships—areas where higher ed excels. Prof. Phillips stresses: "This gives agencies a powerful tool to plan surveillance and limit spread."

Career Opportunities in Invasive Species Research

Curtin's School of Molecular and Life Sciences leads in population genomics, eDNA, and modeling—fields booming amid climate-driven invasions. Projects on foxes, cane toads, and PSHB offer PhD/postdoc roles, often funded by WAARC or government fellowships.

Aspiring researchers can excel as assistants, building skills in supercomputing, R/Shiny apps, and field surveys. Australia-wide, unis seek experts in biosecurity.Learn how to thrive as a research assistant. Check research assistant jobs or Australian uni opportunities.

Photo by Waldemar Brandt on Unsplash

Future Outlook and Actionable Insights

Prospects demand vigilance: human transport remains the wildcard. Solutions include public education on firewood quarantine, host-free planting, and biocontrols like Murdoch University's lab colonies. Curtin's work forecasts scenarios, testing strategies virtually.

Stakeholders should integrate models into policy, fund surveillance, and foster uni-industry ties. Early action could avert catastrophe, preserving Australia's green heritage. Researchers, policymakers, and citizens: use tools like the Survey Planner today.

For deeper dives, read the full paper: Journal of Biogeography DOI. Explore higher ed jobs, rate professors, or career advice to join the fight.