Have you noticed small, round holes appearing in the trunks or branches of trees around Perth?
What may seem like minor damage could be a sign of one of Western Australia’s most serious biosecurity threats, the Polyphagous Shot-Hole Borer. This tiny beetle has the potential to devastate urban forests, street trees, and private gardens across the state. As arborists, we play a critical role in detecting, managing, and helping to prevent its spread. Through expert tree assessments, safe removal practices, and close collaboration with government biosecurity teams, we’re committed to protecting Perth’s environment from this destructive pest.
Understanding the Polyphagous Shot-Hole Borer Threat
The Polyphagous Shot-Hole Borer (PSHB) may be small, but its impact on Western Australia’s trees has been enormous. This invasive beetle species, originally from Southeast Asia, has spread across several continents and was first detected in metropolitan Perth in 2021. Since then, it has triggered extensive biosecurity responses due to the severe damage it causes to both native and ornamental trees.
How the Beetle Damages Trees
The PSHB burrows deep into the trunks and branches of host trees, creating a network of tunnels where it cultivates a symbiotic fungus known as Fusarium euwallaceae. While this fungus provides food for the beetle, it’s devastating for the tree. The fungus blocks the tree’s vascular system, restricting the flow of water and nutrients. Over time, this leads to branch dieback, canopy thinning, and, in many cases, the death of the entire tree.
Even worse, the borer’s tunnelling weakens the structural integrity of the wood, increasing the risk of falling branches and posing safety hazards in residential areas, parks, and along roadsides. This makes early identification and management absolutely critical.
Host Trees and High-Risk Species
The beetle has a wide host range, affecting over 100 tree species worldwide. In Perth, highly susceptible trees include plane trees (Platanus spp.), box elders (Acer negundo), willows, oaks, coral trees, and various species of maples. These are common in both public landscapes and private gardens, meaning the risk extends across residential and commercial properties alike.
By targeting both native and introduced trees, the PSHB threatens not only the visual appeal of Perth’s leafy suburbs but also the ecological health of urban green spaces. Its ability to reproduce rapidly and disperse through infested wood means containment requires coordinated action at every level, from local councils to individual property owners.
Why Early Detection Matters
Once the Polyphagous Shot-Hole Borer establishes itself in a tree, there is no known cure. Infested trees typically need to be removed and destroyed under strict biosecurity protocols to prevent the beetle from spreading further. This makes early detection essential. Arborists trained to recognise the telltale signs, such as tiny entry holes, dark staining, and frass (fine sawdust) around the bark, play a crucial role in containing the infestation before it reaches new areas.
Understanding how the pest behaves is the foundation of an effective response. For that reason, arborists across Perth are being trained to identify PSHB activity, assess high-risk zones, and work alongside government agencies to safeguard the city’s green canopy.
Arborists at the Frontline of Detection and Response
When it comes to managing invasive pests like the Polyphagous Shot-Hole Borer, arborists are the first line of defence. Our knowledge of tree biology, structural health, and environmental stress factors makes us uniquely equipped to detect and respond to outbreaks before they escalate. In many cases, arborists are the first professionals to notice unusual patterns in tree decline, long before the signs become obvious to the public.
The Critical Role of Trained Arborists
Identifying PSHB infestations isn’t a simple visual task. The early symptoms are subtle and can easily be mistaken for fungal infections or mechanical damage. A qualified arborist knows how to differentiate between natural wear and the signature traits of a borer attack, such as:
- Tiny round entry holes about the size of a ballpoint pen tip
- Wet or dark staining beneath the bark caused by fungal activity
- Fine powdery sawdust (known as frass) accumulating around the base of the tree
- Wilting or dieback in the upper canopy despite adequate water
By combining experience with diagnostic precision, arborists can confirm whether a tree requires further testing or immediate removal.
Working with Biosecurity Authorities
In Perth, arborists are playing a direct role in supporting the Department of Primary Industries and Regional Development (DPIRD) with detection and containment measures. Through careful reporting, site documentation, and sample collection, arborists contribute vital data that helps map the spread of the pest and prioritise control zones.
We work closely with local councils, commercial property managers, and residents to ensure all tree work follows biosecurity protocols. When an infestation is confirmed, strict handling and disposal procedures are followed to prevent transporting infested wood or debris to uninfected areas. Every action, from trimming branches to removing stumps, is carried out with precision and care.
Education and Awareness in the Community
Another important role arborists play is education. Many homeowners are unaware of how quickly the PSHB can spread or how easily it can be transferred through firewood, mulch, or untreated green waste. Arborists not only perform technical work but also raise awareness about the importance of proper tree care and compliance with containment guidelines.
At Perth Arbor Services, we consider every inspection an opportunity to inform and empower the community. By helping residents recognise early warning signs and encouraging them to report potential infestations, we strengthen the city’s overall biosecurity resilience.
Arborists are not just tree specialists; they are environmental stewards working at the intersection of science, safety, and sustainability. Their vigilance is essential to safeguarding Perth’s trees and ensuring the success of WA’s broader biosecurity efforts.
Perth Arbor Services’ Case Study: Managing the Infestation
When reports of Polyphagous Shot-Hole Borer activity began surfacing across metropolitan Perth, our team at Perth Arbor Services was engaged by a local council to assess several mature plane trees that were showing early signs of stress. These trees lined a high-traffic street and formed part of a valued urban canopy, providing shade, aesthetic appeal, and environmental benefits to the community. Their decline posed both an environmental and a safety concern, and immediate action was required.
The Situation
Our first step was to carry out a comprehensive on-site inspection. Initial observations revealed telltale signs of borer activity: small round holes in the bark, dark streaking, and patches of frass accumulating at the base of the trees. Given the location and potential risk of spread, we treated the situation as a high-priority case. The local council requested a full arboricultural assessment and confirmation of infestation before determining next steps.
The Assessment
Our qualified arborists conducted a detailed tree inspection, following the protocols set by the Department of Primary Industries and Regional Development (DPIRD). Using specialised tools, we examined the extent of internal damage and collected samples from affected areas for laboratory testing. The results confirmed the presence of the Polyphagous Shot-Hole Borer and its associated fungus, Fusarium euwallaceae.
Each affected tree was assessed for structural stability, potential hazard level, and the likelihood of recovery. Unfortunately, several were found to be too heavily infested to safely remain in place. Immediate containment and removal were required to prevent further spread to nearby healthy trees.
The Response
Working under strict biosecurity and safety guidelines, our team developed a targeted management plan. This included:
- Controlled removal of severely infested trees
- Careful chipping and deep burial of infected material to prevent reinfestation
- Sanitisation of all tools, machinery, and transport vehicles before leaving the site
- Communication with nearby property owners about containment measures and visual indicators of infestation
Throughout the process, our crew maintained full compliance with OH&S standards and provided the council with Safety Method Statements, photographic records, and post-removal verification reports.
The Outcome
The prompt intervention prevented the infestation from spreading to adjacent trees in the same line. Follow-up inspections conducted over the following months showed no new signs of activity, and replacement planting was scheduled with tree species less susceptible to PSHB.
This project demonstrated how professional arborists can effectively coordinate with local councils and government agencies to contain emerging biosecurity threats. For Perth Arbor Services, it reinforced our commitment to evidence-based decision-making, safety, and environmental responsibility, values that continue to guide our work across all sectors.
Our Integrated Approach to Managing Tree Health Threats
The Polyphagous Shot-Hole Borer is only one of many challenges facing Western Australia’s trees. From fungal infections and root decay to structural instability and storm damage, every issue requires a professional, informed approach. At Perth Arbor Services, we take pride in providing an integrated tree management strategy designed to protect, maintain, and enhance tree health across all environments, from private gardens to large-scale public landscapes.
Comprehensive Tree Health Monitoring
We believe prevention is the most effective form of protection. Our team conducts regular monitoring programs for councils, businesses, and residential clients to detect early signs of disease, pest infestation, or structural weakness. Using a combination of visual inspection, risk assessment techniques, and up-to-date diagnostic tools, we help property owners manage problems before they become serious or costly.
By building long-term maintenance schedules, we ensure trees remain healthy, stable, and compliant with local safety regulations. This proactive approach has proven especially effective in areas identified as high-risk zones for pest activity, such as those recently affected by the Polyphagous Shot-Hole Borer.
Safe and Compliant Work Practices
Our commitment to professionalism extends to every stage of our work. Each project is guided by detailed Safety Method Statements and carried out in full compliance with Occupational Health and Safety standards. We operate under a strict policy of environmental responsibility, ensuring that all pruning, removal, and waste disposal methods meet biosecurity and regulatory requirements.
Our equipment, including tipper trucks, Hiab cranes, stump grinders, and chippers, is serviced regularly to guarantee reliability and safety. This ensures that when we manage complex projects, particularly those involving pest containment or hazardous trees, every step is handled efficiently and securely.
Expertise That Spans All Environments
Perth Arbor Services works across a wide range of settings, from private properties to large government and infrastructure projects. Our experience with councils and public works means we understand the high level of documentation, coordination, and accountability required in these environments. Whether responding to a pest outbreak, performing large-scale tree removals, or developing management plans for urban landscapes, we combine technical expertise with clear communication and dependable service delivery.
Commitment to Best Practice and Industry Standards
Tony Head and Michael Dawson founded Perth Arbor Services on the belief that Perth’s arboricultural industry could operate with greater professionalism and care. Today, that philosophy underpins everything we do. Our qualified arborists stay up to date with current research, training, and biosecurity procedures, ensuring that our clients always receive advice and service grounded in the latest best practices.
Through our integrated, science-driven approach, we continue to protect Western Australia’s trees while promoting safer, healthier, and more sustainable environments for the future.
Supporting WA’s Biosecurity and Urban Forest Future
As Western Australia continues to respond to the growing threat of the Polyphagous Shot-Hole Borer, collaboration and vigilance are more important than ever. Arborists, councils, and community members all play a vital role in protecting our shared environment. At Perth Arbor Services, we’re proud to be part of that collective effort, working not only to manage current infestations but also to strengthen the long-term resilience of Perth’s urban forests.
Collaboration with Government and Industry Partners
We regularly work alongside the Department of Primary Industries and Regional Development (DPIRD), local councils, and other professional bodies to ensure that all arboricultural work aligns with current biosecurity protocols. By sharing data, expertise, and field observations, we contribute to the state’s broader monitoring and control initiatives. This level of collaboration helps authorities respond faster, target affected areas more accurately, and prevent unnecessary tree loss.
Through our involvement in council projects and large-scale assessments, we’ve seen firsthand how coordinated action makes a difference. Early reporting and professional tree inspection remain the most effective tools in preventing widespread outbreaks, and our team continues to support these objectives at every opportunity.
Educating the Community on Tree Health and Biosecurity
Public awareness is a powerful defence against invasive pests. Many infestations spread because early warning signs go unnoticed or are mistaken for normal tree decline. We’re committed to educating homeowners, businesses, and public agencies about what to look for, how to report concerns, and why engaging a qualified arborist is essential.
Our goal is to create a culture of shared responsibility where everyone, from residents to developers, understands their role in maintaining a healthy urban canopy. Simple actions like avoiding the movement of untreated firewood, reporting unusual damage, or scheduling annual tree inspections can significantly reduce the spread of pests like the PSHB.
A Long-Term Vision for Perth’s Urban Forest
The preservation of Perth’s trees goes beyond pest management. It’s about sustaining the green infrastructure that defines our city’s character and liveability. Mature trees cool our streets, absorb carbon, provide habitat for wildlife, and enrich our communities. Protecting them from threats like the Polyphagous Shot-Hole Borer is an investment in Perth’s environmental and social future.
At Perth Arbor Services, we see ourselves not just as service providers but as custodians of that legacy. Our commitment to safety, science, and sustainability ensures that we continue to play a meaningful role in strengthening Western Australia’s biosecurity and preserving its natural heritage for generations to come.
Protecting Perth’s Trees Starts with Awareness
Have you noticed signs of stress or unusual damage on trees around your property?
Acting early could be the difference between containment and widespread loss. The Polyphagous Shot-Hole Borer represents one of the most serious threats to Western Australia’s trees, but with the right expertise, it can be managed effectively.
At Perth Arbor Services, we combine technical precision, local knowledge, and a strong commitment to best practice to help safeguard our city’s green canopy. From identifying early infestations to coordinating large-scale management plans, we stand ready to support councils, businesses, and residents in protecting Perth’s environment. Together, we can strengthen biosecurity, preserve biodiversity, and ensure our urban forests continue to thrive for generations to come.