PSHB Biosecurity — What Every Perth Tree Buyer Needs to Know

Perth is managing a permanent infestation of Polyphagous Shot-Hole Borer.
The WA Government’s Quarantine Area covers the entire metropolitan region.
Before purchasing any tree for your Treebate claim, one biosecurity check
is non-negotiable.

2021

Year PSHB was first detected in Perth

T2M

Transition to Management — eradication no longer feasible

2

Quarantine zones — Management Zone and Containment Zone

v6

Current DPIRD WA Host List — updated 30 June 2025

What Is Polyphagous Shot-Hole Borer?

Polyphagous Shot-Hole Borer (PSHB) is a small invasive beetle — roughly the
size of a sesame seed — that bores into trees, spreads a damaging Fusarium
fungus, and in susceptible species causes dieback and death. It was detected
in Perth in August 2021 and is now permanently established across the
metropolitan area.

In November 2025, the national PSHB response formally transitioned from
eradication to Transition to Management (T2M). PSHB is now a permanent
management situation in WA. The Quarantine Area covers the entire Perth
metropolitan area and is divided into two zones with different restrictions.

Knowing your zone is the single most important step before purchasing any
tree — whether you are claiming Treebate, the WA Tree Recovery Program, or
simply replanting your garden.

Understanding Your PSHB Zone

🔴 Management Zone
Inner metropolitan Perth
The area of known, confirmed PSHB infestation. The highest restriction tier. Hard-stops apply to all Reproductive Hosts at any susceptibility level.

What this means for your Treebate purchase: Several popular species — including Red Flowering Gum and Agonis flexuosa — are blocked for Management Zone customers. Use our Tree Selection Tool to get a confirmed-safe shortlist for your suburb.
🟡 Containment Zone
Outer metropolitan buffer area
The buffer zone surrounding the Management Zone. Active surveillance area. Hard-stops apply to Extreme and Very High Reproductive Hosts. Manual Review required for High Reproductive Hosts.

What this means for your Treebate purchase: More species are available than in the Management Zone, but restrictions still apply. Always check your suburb before purchasing.
✅ Outside Quarantine Area
Beyond the Perth metropolitan QA boundary
Standard Treebate eligibility rules apply. PSHB biosecurity screen still runs — flag if species is Extreme or Very High risk nationally. Always verify your suburb before purchasing as zone boundaries can change.

Species × Zone Decision Matrix

This matrix governs every species decision on treebate.com.au. A blocked
sale is a biosecurity compliance event — never a lost sale.

Customer Zone Extreme / Very High High Reproductive Moderate Non-Reproductive
Management Zone 🔴 Hard-stop 🔴 Hard-stop 🟡 Manual review ✅ Proceed
Containment Zone 🔴 Hard-stop 🟡 Manual review 🟡 Manual review ✅ Proceed
Outside QA 🟡 Flag + advise ✅ Proceed ✅ Proceed ✅ Proceed

Proceed = subject to all other Treebate eligibility rules (3m+ height, ABN invoice, etc.)

Hard-Stop Species — Blocked for QA Customers

These species are blocked for all customers in the PSHB Quarantine Area.
The system explains the risk and offers PSHB-safe alternatives. A blocked
sale is recorded as a Biosecurity Compliance Event — never a lost sale.

Botanical Name Common Name Susceptibility Action
Melaleuca rhaphiophyllaSwamp paperbarkVery HighHard-stop all QA
Talipariti tiliaceumSea hibiscusVery HighHard-stop all QA
Banksia littoralisSwamp banksiaHighHard-stop Mgmt / Review Containment
Corymbia calophyllaMarriHighHard-stop Mgmt / Review Containment
Corymbia ficifoliaRed flowering gumHighHard-stop Mgmt / Review Containment
Melaleuca preissianaStout paperbarkHighHard-stop Mgmt / Review Containment

🚨 Special Flag — Agonis flexuosa (Willow Myrtle) — Permanent Hard-Stop All Zones

DWER's own promotional materials for the Treebate program have featured Agonis flexuosa imagery. treebate.com.au applies a stricter biosecurity standard than government promotional materials.

While classified as Negligible non-reproductive on the DPIRD host list, any species appearing on that list — regardless of susceptibility tier — is flagged in our system. This position is non-negotiable regardless of DWER imagery or customer pressure.

treebate.com.au's biosecurity standard deliberately exceeds DWER's own promotional materials. DWER imagery or copy is not a reliable compliance source.

PSHB-Safe Recommended Alternatives

These species are confirmed Non-Reproductive Hosts — PSHB cannot successfully
reproduce in them. All are safe for Management Zone and Containment Zone
customers. The 3m+ height filter still applies before purchasing.

Botanical Name Common Name PSHB Status Height
Banksia grandisBull Banksia✅ Negligible5–10m
Banksia menziesiiFirewood Banksia✅ Negligible4–10m
Eucalyptus gomphocephalaTuart✅ Negligible10–25m
Hakea multilineataGrass-leaf Hakea✅ Negligible3–4m
Hakea laurinaPincushion Hakea✅ Not listed4–6m
Grevillea olivaceaOlive Grevillea✅ Negligible3–5m
Callistachys lanceolataWonnich✅ Low3–7m
Eucalyptus torquataCoral Gum✅ Not listed4–6m

Movement Restrictions — BAM Act 2007

The Quarantine Area Notice (QAN) issued under BAM Act 2007 powers restricts
movement of host plant material across zone boundaries. treebate.com.au
operates Click-and-Collect only — customers collect from a Partner Nursery
within their own zone. This is not a service limitation — it is BAM Act compliance.

Movement of the following is prohibited across zone boundaries: unseasoned
wood, green waste over 2.5cm diameter, live plants with woody stems over 2cm
diameter, and mulch and wood chip material.

MovementStatus
Management Zone → Containment Zone🔴 Prohibited
Management Zone → Outside QA🔴 Prohibited
Containment Zone → Outside QA🔴 Prohibited
Within Management Zone🟡 Permitted subject to QAN
Within Containment Zone🟡 Permitted subject to QAN

⚠ Reporting Suspected PSHB — Your Legal Obligation

Any person who finds or suspects PSHB must report it to DPIRD immediately under the Biosecurity and Agriculture Management Act 2007 (BAM Act).

Do not remove a PSHB-affected tree without DPIRD authorisation. Unauthorised removal may void your WA Tree Recovery Program eligibility — you need the DPIRD Tree ID issued at time of authorised removal to claim the rebate.

Report via: MyPestGuide Reporter app or call PaDIS on (08) 9368 3080 or email padis@dpird.wa.gov.au

Read the Full Biosecurity Guides

PSHB Perth Zones — The Complete Guide

Plain-English zone guide for Perth homeowners — Management Zone, Containment Zone, and what each means for your Treebate tree choice.

The Beetle That Beat Us — PSHB Explained

Everything Perth tree owners need to know about Polyphagous Shot-Hole Borer — how it spreads, what it kills, and how to protect your garden.

Source authority: DPIRD PSHB WA Host List Version 6, 30 June 2025.
Governing legislation: Biosecurity and Agriculture Management Act 2007 (BAM Act).
treebate.com.au is an independent guide and is not affiliated with DWER, DPIRD,
or the WA Government. Zone boundaries and host status are subject to change —
always verify at dpird.wa.gov.au/pshb before purchasing.

Scroll to Top