WA government changes tack in borer battle, but is it ‘too little, too late’?

The West Australian government’s capitulation in the fight to eradicate an invasive pest responsible for the removal of some of Perth’s grandest trees has been decried as “tragic”, and newly announced research funding lashed as “too little, too late”.

Agriculture Minister Jackie Jarvis revealed the change in strategy on Thursday morning after a meeting of the National Management Group the day prior deemed it was no longer technically feasible to eradicate the polyphagous shot-hole borer.

Stumps left behind after tree removal along Mounts Bay Road due to an infestation of the polyphagous shot-hole borer.Credit: Ross Swanborough

Instead, the government has shifted to a “management” approach that will focus on limiting its spread.

But Invasive Species Council policy director Dr Carol Booth said it was tragic news with 15 native tree species in WA identified as “highly or very highly susceptible” to the shot-hole borer.

These included iconic species like paperbarks, banksias and eucalypts.

“Another 23 species are moderately susceptible, and that’s just in WA. It implies hundreds of native species across the country could be at risk if the borer spreads,” Booth said.

“We are also gravely concerned about the loss of urban trees, which provide vital habitat, shade, beauty and health benefits in our cities and towns. The environmental and social toll could be immense.

“Now that eradication is off the table, the priority must be stopping the borer from spreading beyond the Perth region.”

The borer, a sesame seed-sized beetle that rapidly multiplies and kills trees through the fungus it harvests and feeds on, was first detected in Fremantle four years ago.

Despite a mammoth effort – which included the removal of dozens of old trees including large figs along the Mount Eliza escarpment in Kings Park and in Hyde Park in Mount Lawley – Premier Roger Cook in January conceded eradication was a “tough battle”.

Jarvis on Thursday said the government’s strategy would shift to explore “alternative solutions by supporting local scientists to undertake more research under WA conditions”.

The government has set aside $26.5 million for the shot-hole borer response plan in Thursday’s state budget, which would focus on slowing its spread and protecting the state’s horticulture industry.

It will also fund three new research projects focused on limiting the borer’s spread through the WA Agricultural Research Collaboration.

Department of Primary Industries and Regional Development deputy director-general Mia Carbon said the difficulty in detecting and controlling new infestations before the borer could reproduce, and a lack of chemical treatments to kill the pest, were key factors in the change in strategy.

“Ongoing eradication efforts would require the removal of a significant number of trees from Perth’s urban canopy and, given the biology and behaviour of the pest in the WA environment, are unlikely to be successful long term,” she said.

Meanwhile, opposition agriculture spokesman Lachlan Hunter called for Jarvis to be stripped of her portfolio, while local government spokeswoman Kirrilee Warr said the department had acted too slow and put an unfair burden on local governments.

“Throwing money at a pest that has already gotten away won’t take us very far,” Hunter said.

“This funding is too little, too late. Where was this level of urgency when it could have made a difference?”

Warr’s comments echoed frustrations voiced by local governments late last year, when they accused the state of not pulling its weight in the fight against the invasive pest.

The WA Local Government Association’s pre-election wishlist released in September urged Labor to boost signage to increase awareness of the borer outside the Perth metro quarantine zones.

At the same time, the Shire of Mundaring passed a motion giving its chief executive authority to plead with Main Roads WA for LED signage along Great Eastern Highway alerting drivers to the quarantine zone and rules.

The shire’s motion also called for escalated research efforts and partnerships with neighbouring councils and government agencies to launch a community awareness campaign.

Opposition Leader Basil Zempilas said the government was trying to convince West Australians it “should be applauded for trying to slow the spread of something they failed to contain in the first place”.

WA Agricultural Research Collaboration director Kelly Pearce said research in the state announced on Thursday was critical to learn more about the borer and find alternative solutions.

The three research projects will focus on improved control strategies, detection and surveillance, and bettering the understanding of host biology, and will be driven, respectively, by Curtin University, Murdoch University, and the University of WA.

with Hamish Hastie

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