Polyphagous Shot-Hole Borer and Your Perth Trees

What polyphagous shot-hole borer is

Polyphagous shot-hole borer, usually shortened to PSHB, is an exotic beetle pest that bores into trees. "Polyphagous" means it is not fussy about its host: it can attack a wide range of tree species. "Shot-hole" refers to the small entry holes it leaves in the bark.

It is a biosecurity issue rather than just a garden pest, which is why the rules below come from the Department of Primary Industries and Regional Development (DPIRD) rather than your council. This guide summarises DPIRD's published position as at September 2026. The official pages are listed at the end, and they are the place to check before acting.

Where things stand in 2026

The original aim was to eradicate PSHB from Perth. That changed in 2025.

• Eradication is off the table. DPIRD says eradication was found to be no longer technically feasible.
• Transition to Management since 1 July 2025. The response moved to a Transition to Management phase from that date. The national plan for this phase runs for about 18 months.
• The quarantine area stays. DPIRD says the quarantine area remains in place and covers the entire Perth metropolitan area. It was extended to the whole metro in September 2024.
• Funding continues. The 2025-26 State Budget provisioned $26.5 million for the response, with $2.17 million committed to research.

For homeowners, the practical change is the next one.

Landowners are now responsible

DPIRD's position is that all landowners and managers in the Perth metropolitan area are now responsible for managing borer-affected trees. DPIRD has stopped its own pruning and removal of affected trees in the Management Zone, and in the Containment Zone it removes trees on a case-by-case basis.

In plain terms: if a tree on your block has borer, dealing with it is now generally your job and your cost, in the same way as any other sick or dangerous tree.

The two zones

The quarantine area is split into two zones:

• The Management Zone is the inner metro area where the borer is known to be established.
• The Containment Zone is the outer metro buffer around it.

Which zone your property is in decides which movement rules apply, and it can matter for what DPIRD does about a reported tree. We are not going to tell you which zone a suburb falls in. Zone boundaries follow a map rather than suburb names, and DPIRD updates the map. Check your address on DPIRD's current quarantine map before you move wood or book work.

Signs to look for

DPIRD asks people to keep an eye on their trees and report anything suspicious. Without trying to turn you into an entomologist, the things worth noticing are:

• Small entry holes in the trunk or branches.
• Staining or gumming on the bark around the holes.
• Branch dieback, where limbs wilt, lose leaves or die back without an obvious cause.

None of these on its own proves borer is present. Other insects, fungal problems and plain drought stress can look similar, especially at the end of a long Perth summer. That is why DPIRD asks for photos and a report rather than a DIY diagnosis.

The City of Joondalup gives useful advice for anyone pruning: check trees before and after pruning, and if you see suspicious symptoms, leave the plant or the prunings on your property and report them to DPIRD straight away. That applies anywhere in Perth.

How to report a suspect tree

DPIRD gives three ways to report:

• MyPestGuide Reporter app. Take photos and submit them from your phone.
• Phone PaDIS, DPIRD's Pest and Disease Information Service, on (08) 9368 3080.
• Email padis@dpird.wa.gov.au.

When you take photos:

1. Get a close-up of the holes with a pen or ruler in the shot, so the size is clear.
2. Take a wider photo of the whole trunk or branch.
3. Take one of the whole tree, so the species and its overall condition can be seen.
4. Note the address and the date.

Until you hear back, do not move cut branches, logs or prunings off the property.

Moving wood and green waste

This is where PSHB touches almost every tree job in Perth. DPIRD's movement rules for the Management Zone are:

DPIRD publishes a list of exempt waste facilities that can take green waste under these rules. Check that list before you load a trailer.

Firewood

DPIRD says untreated wood, including firewood, and living plants cannot be moved outside the quarantine area. Its advice is to buy firewood locally and burn it where you bought it. If a tree is coming down and someone has offered to take the logs for firewood in the country, that is exactly the kind of movement the rules are designed to stop.

Verge collections and bins

Bulk green-waste verge collections still run in many Perth councils, but each council sets its own size limits and dates. If you are putting out branches from a tree you suspect has borer, report it first and follow DPIRD's advice rather than leaving it on the verge. Joondalup residents, for example, get green-waste tipping vouchers each year; our Joondalup page has more on that area.

What this means when you book tree work

PSHB does not stop you pruning or removing a tree. It does mean the question of where the wood goes is part of the job, not an afterthought. When you ask for a quote, it is reasonable to ask:

• How will the green waste be handled? Will branches be chipped on site, and how fine?
• Where is it going? To an exempt facility, to another site within the zone, or staying on your block as mulch?
• How is it transported? Sealed and covered, as DPIRD requires for green waste going to exempt facilities.
• Is the gear cleaned? Machinery that handled wood must be cleaned before it leaves the Management Zone.
• What about the logs? Who takes them, and where to.
• What if they find borer mid-job? A sensible answer is to stop, keep the material on site, photograph it and report it.

A written quote should say what happens to the logs, branches and mulch. If you are keeping the mulch on your own property, say so when you book. Our tree removal service and tree pruning service pages explain what a quote normally covers.

Green-waste handling is one of the factors that moves the price of a job, along with height, access and whether the stump is ground. The tree removal cost guide sets out 2026 planning bands.

How a borer-aware job usually runs

Putting DPIRD's rules and the Joondalup advice together, a sensible job in the quarantine area looks something like this:

1. Look before cutting. The arborist checks the tree for entry holes, staining and dieback before the first cut, and again as branches come down.
2. Stop if something looks wrong. If there are suspicious symptoms, the material stays on your property, photos are taken with a pen or ruler for scale, and the tree is reported to DPIRD before anything is moved.
3. Chip on site where it makes sense. DPIRD's limit for wood leaving the Management Zone is chips of 2.5 cm or less, and mulch you keep stays on your own block.
4. Load and cover. Green waste heading to an exempt facility goes in a fully sealed and covered skip, trailer or truck.
5. Clean up the gear. Machinery that has handled wood or plant material is cleaned before it leaves the Management Zone.

If the answers you get to the questions above line up with these steps, the green waste side of the job is in hand.

Removal is not always the answer

Do not rush to remove a tree on suspicion alone. Report it, see what DPIRD advises, and get an arborist to look at the tree's overall structure before deciding. If a heavily affected tree has become unsafe, removal may be the right call, and your council's tree rules still apply. Our guide on whether you can cut down a tree in Perth covers those.

Replanting

The state has funded a WA Tree Recovery Program to help councils and residential landowners replant trees removed because of PSHB. Check with DPIRD whether it is still open before you plan around it.

The short version

• The whole Perth metro is a PSHB quarantine area, split into a Management Zone and a Containment Zone. Check your address on DPIRD's map.
• Landowners are now responsible for managing borer-affected trees.
• Look for small entry holes, staining or gumming, and branch dieback.
• Report through MyPestGuide, PaDIS on (08) 9368 3080 or padis@dpird.wa.gov.au, with photos that include a pen or ruler.
• Wood leaving the Management Zone must be chipped to 2.5 cm or less, plant material over 2 cm cannot leave it, and green waste to exempt facilities must be sealed and covered.
• Do not move firewood out of the quarantine area.
• When you book tree work, ask how the green waste will be handled.

Rules can change as the Transition to Management phase continues. Treat this page as a summary and check DPIRD's pages for the current position.