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Polyphagous shot-hole borer

Learn the signs and how to make a report if you find or suspect the presence of Polyphagous shot-hole borer (Euwallacea fornicatus) in Western Australia.

A polyphagous shot-hole borer (small beetle) on tree bark
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Polyphagous shot-hole borer

Pests & insects

Polyphagous shot-hole borer is an invasive beetle species that infests a wide range of trees, causing damage by boring into the wood and spreading pathogenic fungi. A Quarantine Area divided into two zones is in place with rules applied to the movement of wood or plant materials. 

Updated: 12 November 2025
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Frontal shot of infested plant material.
Polyphagous shot-hole borer kills vascular tissue in trees causing dieback and tree death.

About the Polyphagous shot-hole borer

Polyphagous shot-hole borer (PSHB, Euwallacea fornicatus) is a small (approx. 1mm long) beetle native to Southeast Asia that tunnels into the trunks, stems and branches of trees and plants. This beetle is highly invasive and attacks a wide range of plant species, with over 500 documented globally to have been affected. 

The department is responding to a detection of this invasive pest in the Perth metropolitan area and has implemented a Quarantine Area (QA). This restriction aims to prevent the spread of the pest by limiting the movement of wood and plant materials.

PSHB was detected in WA in August 2021. Since then, the department has been leading a nationally funded and coordinated biosecurity response. Allowing this pest to spread in WA could have a significant impact on our urban canopy and may pose a threat to our valuable agricultural industry.

Current Situation

The national response to polyphagous shot-hole borer (PSHB) is transitioning from an eradication strategy to a long-term management approach after the National Management Group determined the borer was no longer technically feasible to eradicate.

A national Transition to Management (T2M) response plan is now in place and is being delivered by DPIRD.

This phase of the response includes development and implementation of strategies to slow the spread of PSHB through targeted surveillance, the creation of an Integrated Pest Management Program and provision of support and training for landowners to build capacity for long term management of the pest.

Under the national T2M response plan, DPIRD’s tree pruning and removal program will focus on trees in the outer Perth metropolitan area that pose a risk of spreading the borer outside of the Quarantine Area (QA). All other landowners and managers in the Perth metropolitan area are now responsible for managing borer-affected trees.

DPIRD is committed to protecting Perth’s urban tree canopy and WA’s horticulture industry by working closely with local governments, community groups and industry bodies to build resilience against PSHB.

A new Quarantine Area Notice (QAN), to support the T2M phase of the response, has come into effect. The QAN covers the entire Perth metropolitan area. Movement restrictions on Firewood, green waste, live plants and plant material still apply to help prevent the spread of PSHB.

Suspect an infestation?

Report a suspected PSHB infestation by using the MyPestGuide® Reporter app.

Report via MyPestGuide

Quarantine Area

A Quarantine Area (QA) covering the entire Perth metropolitan area is in place, with restrictions on the movement of wood, green waste, mulch, live plants and plant material.

The QA is split into two zones:

  • The Management Zone which covers the inner metropolitan area and is the area of known borer infestation; and
  • The Containment Zone which is the area between the Management Zone and the outer boundary of the QA.

Movement Restrictions

To limit the spread of shot-hole borer, the following restrictions apply to the movement of host plant material:

  • Host plant material must not be moved from the Management Zone to the Containment Zone or to outside the QA.
  • Host plant material must not be moved from within the QA to outside the QA.
  • Any machinery, equipment and vehicles used in the processing or handling of wood, including wood mulching and chipping, must be cleaned of all wood and plant material before being moved into the Containment Zone or outside of the QA.

These restrictions apply to host plant material such as unseasoned wood, green waste and mulch that is larger than 2.5 cm in diameter, and live plants with woody stems greater than 2 cm in diameter.

Enter an address into the interactive map below to see which zone and restrictions apply.

What plants are affected?

PSHB causes serious damage to many types of trees and plants with a global host list covering over 500 species. When infested, a plant can show symptoms such as dieback, shotholes, galleries, frass and gumming.

Reproductive hosts are susceptible trees in which both the beetle and the fungus successfully establish and reproduce. The global host list is extensive with over 100 reproductive hosts.

View the list of affected plants and trees in Western Australia

WA Tree Recovery Program 

Western Australians impacted by PSHB can now access rebates to support replanting trees on their properties.

 

The WA Tree Recovery Program is a $7.2 million program, led by the Department of Water and Environmental Regulation, to help boost Perth's canopy cover.

 

The program is supporting replanting initiatives by local governments, residents and the Perth Zoo.

 

Grants provided to local governments support the replanting of three trees for every tree lost to PSHB.

 

Under the residential rebate program, eligible Western Australian landowners can claim up to $150 for every tree removed under DPIRD authorisation as a result of PSHB.

 

For more information, please visit https://www.wa.gov.au/service/environment/conservation/wa-tree-recovery  

Keep an eye out

Detection of PSHB can be difficult as they are very small – roughly the size of a sesame seed. However, there are several symptoms that can indicate a plant may be infested.

Watch the animation below on YouTube to learn more and find out how to report PSHB sightings.

 

How does PSHB spread?

PSHB is a tree-boring beetle that has a symbiotic relationship with a Fusarium fungus. It cultivates this fungus inside of plants as a food source for themselves and their larvae. In susceptible species, the fungus kills the plant by restricting or preventing the movement of water and nutrients. This causes symptoms such as Fusarium dieback that eventually leads to plant death. The beetle also causes structural damage by creating tunnels, known as galleries, throughout the plant.

Native to Southeast Asia, PSHB has spread to countries including Israel, the USA South Africa and Argentina, and is now in WA. It is possible PSHB ‘hitchhiked’ its way to Australia on untreated wooden articles and packaging materials. Subsequent spread can be aided by the movement of infested wood (such as pruned trees or unseasoned firewood).

Actions to minimise the spread

Legal duty to report

Euwallacea fornicatus (Eichhoff, 1868) is a declared pest in WA. It is a prohibited organism under section 12 of the Biosecurity and Agriculture Management Act 2007. 

This means that any person who finds or suspects the presence of polyphagous shot-hole borer must report it to the department.

Report suspect pests

Early detection and reporting will help protect WA trees. If you find or suspect the presence of PSHB, report it in one of the following ways. Note: Please include a ballpoint pen or ruler in photos of bore holes. This assists us in assessing the size of the bore holes.

More information