Managing waste wisely

Managing the risk of the Polyphagous shot-hole borer

Signs a tree is infested with the Polyphagous shot-hole borer

The mulch we provide to our member council residents is free of the shot-hole borer beetle. Find out more about the beetle and what the spread means for our local area.

What is the shot-hole borer beetle?

Polyphagous shot-hole borer (PSHB, Euwallacea fornicatus) is a small beetle native to Southeast Asia that tunnels into the trunks, stems and branches of trees and plants. PSHB has a symbiotic relationship with a Furasim fungus, cultivating the fungus inside of plants as a food source. This fungus kills susceptible trees by blocking the vital transport of water and nutrients. Trees that are infested by PSHB are a public safety hazard and provide a constant source of PSHB beetles that disperse to neighbouring trees.

This highly invasive pest was first detected in the Perth metropolitan area in August 2021. If the pest is established in WA, then it would have a significant impact on the Perth urban canopy as well as posing a threat to the WA agricultural industry.

What is the government doing to combat the shot-hole borer beetle?

DPIRD (the Department of Primary Industries and Regional Development) has made the Perth Metropolitan area a quarantine zone to limit the movement of wood and plant materials. They are also leading an eradication response to this pest. As no effective chemical treatment exists for control, DPIRD are focusing on removing infested trees and tree branches to stop the spread. By removing infected trees, many other healthy trees will be saved.

What is the WMRC doing to combat the shot-hole borer beetle?

WMRC provides free mulch for Member Council residents that is free of the Polyphagous shot-hole borer.

The West Metro Recycling Centre collects green waste and sends it for processing at the Western Tree Recyclers facility, a DPIRD-approved green waste site. All mulch provided by the West Metro Recycling Centre has gone through two grinds at Western Tree Recyclers, ensuring it is ground to less than 2.5cm in size. The first grind kills all shot-hole borer beetles and larvae. The second pass through the grinder creates a finer ground material.

DPIRD-approved green waste sites are under the general exemption outlined in the PSHB Quarantine Area Notice. These facilities are regularly inspected by DPIRD to ensure that plant material is managed in accordance with the requirements of the Quarantine Area Notice.

What can I do to help?

Please take the following actions to limit the spread of the shot-hole borer beetle:

  1. Do not move plant material, untreated or unseasoned wood outside the quarantine zone unless chipped to less than 2.5cm in diameter. Find out more about what you can and can’t do in the quarantine zone here: Quarantine buffer offers more protection for WA trees
  2. Learn how to spot an infected tree and report infected trees to DPIRD via the MyPestGuide® Reporter app or by contacting the Pest and Disease Information Service on 9368 3080 or by email to padis@dpird.wa.gov.au.
  3. Avoid planting tree species that are most likely to be impacted by shot-hole borer. Find the list of trees to avoid here.
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