“Learn to live with it” is a phrase we heard a lot in the latter stages of the COVID-19 pandemic.
It’s an acceptance that while something bad is happening, there comes a point where the mindset needs to shift.
That phrase is now starting to be spoken about in regards to the biggest biosecurity response in WA’s history — managing the shot-hole-borer.
It’s been three years since the invasive pathogen began killing trees across Perth, and authorities are sticking to one method — cutting down infected trees.
Despite its small size, the shot-hole borer beetle can destroy a tree in just two years. (ABC News)
Perth has lost more than 3,600 trees in that time, but the borer has persisted.
The strategy is one of eradication — with no silver bullet fix in sight, experts are asking how many trees are we willing to lose before we learn to live with the beetle?
Experts call for alternative methods
The tiny pest, native to South-East Asia, was first detected in Fremantle in 2021.
Despite its size, the beetle and its accompanying fungus can kill a tree within two years by blocking the flow of water and nutrients.
The tree will likely be cut or pruned before then, as that’s currently the only proven way to kill the borer.
A large tree infected with polyphagous shot-hole borer being pruned or chopped in Perth’s Kings Park. (ABC News: Grace Burmas)
Whether it’s a beloved Ficus in a leafy suburb or the iconic Morton Bay fig trees in Kings Park, the shot-hole borer is changing the city’s canopy, which is already the barest in the country.
Calls for more research into alternative methods have echoed through the media.
Most of the scrutiny has been directed at WA’s Department of Primary Industries and Regional Development (DPIRD), which is responsible for the work on the ground.
But if the department wanted to make changes to the response plan, there’s a bit of a process.
It would have to report to a national technical committee, which then advises the National Management Group (NMG) which ultimately makes the key decisions for the biosecurity response.
It’s up to the NMG to draw the line in the sand and stop the chop.
But the federal agriculture department said all the evidence suggests chopping or pruning trees is still an appropriate measure to eradicate the borer.
Efforts are underway in Kings Park to curb the spread of the shot-hole borer. (ABC News: West Matteeussen)
“The response plan includes several triggers and milestone reporting over the three-year period to ensure the program continues to meet the outlined objectives,” a department spokesperson said.
The emergency response plan could transition to a management phase at any point, if the NMG and committee agreed eradication was no longer feasible.
“The NMG will only make this decision based on scientific technical advice from the Consultative Committee on Emergency Plant Pests that it is no longer technically feasible.”
MP wants money spent wisely
The debate over what to do about the shot-hole borer has been simmering at a local and state government level, but Independent MP, Kate Chaney, has taken the matter to Parliament.
Every state in the country is contributing to the $44 million fund and Ms Chaney is focused on making sure it’s spent appropriately.
“Eradication is a really resource-intensive approach so if we’re going to follow that path, we need to know that it’s working and that it’s actually worth it,” she said.
Ms Chaney called for an open-minded approach to find new ways to manage the pest.
Independent MP, Kate Chaney, wants to see more research done into ways of managing the shot-hole borer. (ABC News: Grace Burmas)
“Given no other country in the world has attempted to eradicate this, we need to do the research here,” she said.
“We’re also now seeing that the borer affects native species and its potential impact if it spreads across Australia is huge so I think it should be a national priority to understand this better.”
No silver bullet
The sentiment among local experts and councils is clear – we need to eradicate this pest but it’s not going happen by cutting down every tree that crosses its path.
Tom Robinson is an arborist working with local governments to trial alternative solutions.
Arborist Tom Robinson is working with local councils to trial chemical treatments to polyphagous shot-hole borer. (ABC News: Grace Burmas)
“If we’re removing large mature trees to eradicate the pest, which is not ultimately possible, we end up cutting down most of the trees in Perth for a goal that’s unachievable,” he said.
Mr Robinson’s team has had promising results using pesticides to kill the beetle after it’s burrowed into the tree.
“There’s been no silver bullet, and I don’t think there will be, but what we’re looking for is kind of that integrated pest management strategy where you’ve got several different options that you can use so we can manage it,” he said.
Traps have been set in Kings Park to try and stop the shot-hole borer. (ABC News: West Matteeussen)
Perth may never be completely clear of the shot-hole borer and given it’s the size of a sesame seed it’s going to be hard to tell if it’s been eradicated.
“I think our best option is to say, well, we’ve got no current symptomatic trees,” Mr Robinson said
