Community needs to stay vigilant on polyphagous shot-hole borer threat to South West region
![The polyphagous shot-hole borer is just 2mm in size but leads to dieback in trees due to its burrowing and symbiotic relationship with a fungus.](https://images.thewest.com.au/publication/C-15449161/4eb452391f0766452ad7ccd1564da6bcf20d7f16-16x9-x0y114w2200h1238.jpg?imwidth=810&impolicy=wan_v3)
The South West region could be the next area to face the wrath of a tiny exotic beetle which has already led to the removal of thousands of trees in metropolitan Perth.
The polyphagous shot-hole borer was first detected in the Perth metropolitan area in 2021 and has since led to infestation of more than 6000 trees.
Speaking on Sunday, WA Liberal candidate for Riverton and Canning deputy mayor Amanda Spencer-Teo said the South West region should brace for impact.
“It’s not a case of if this gets down to the South West but it’s a case of when,” she said.
“It is going to be an absolute agricultural nightmare.”
![Pictures of WA Liberal Leader Libby Mettam with Basil Zempilas, Liberal Candidate for Churchlands and Lord Mayor of Perth, and Amanda Spencer-Teo, Liberal Candidate for Riverton, outside Council House with a larger fig tree behind that has been attacked by the borer in Perth.](https://images.thewest.com.au/publication/C-15449161/53de1f2d4c9c68cca44c3ddd1fe6bddd125f4435.jpg?imwidth=810&impolicy=wan_v3)
The insect is native to South-East Asia but has spread as far as Argentina, the USA and South Africa.
Native trees aren’t all immune to the beetle, with marri and karri trees among the more than 30 native species at risk.
According to the Department of Primary Industries and Regional Development, more than 1.8 million trees have been inspected Statewide — a record for the organisation.
A DPIRD spokesperson said an “unprecedented biosecurity response” was under way to monitor the problem.
“Currently there have been no detections of PSHB in the South West,” they said.
“A surveillance program is under way, which includes 51 PSHB traps deployed across the South West, including Bunbury, Donnybrook, Balingup, Bridgetown and Manjimup.”
There is a quarantine zone around the Perth metro area and Rottnest Island which spans as far south as Hammond Park.
Untreated wood which is not chipped to less than 2.5cm in diameter or living plants with woody stems greater than 2cm in diameter may not leave the area without a permit.
South West NRM sustainability and environment lead Linda Metz said there had been no reports of the insect in the South West, and it was best to keep it that way.
“SWNRM does ... encourage people to be aware of the potential for spread and what they can personally do to prevent infested material from coming into the South West,” he said.
“Our advice includes avoiding bringing any plant material from the quarantine zone into the South West.
“This could be things like firewood, plants and plant cuttings that you might pick up on Facebook Marketplace or bring to a holiday home, and untreated wood products.”
More than $44 million has been committed by the State Government through a cost-sharing arrangement with the Federal Government.
The DPIRD spokesperson said the community was a crucial part of the response, with reports to be made via the department’s MyPestGuide Reporter app or via the Pest and Disease Information Service on 9368 3080 or padis@dpird.wa.gov.au.
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