On the left, the polyphagous shot-hole borer, which has devastated Perth’s urban tree canopy. Unfortunately, as a result, thousands of trees have been lost. The Western Australian government has been left to grapple with the pest’s unstoppable advance. In an inconvenient truth, recent proclamations of failure brought about by erasure efforts have created a real need for tactical pivot. Authorities have committed at least $26.5 million, widely reported as “for response measures.” Today, they’re working to stop new incursions into native forests.
The WA government has signalled it intends to keep at least two quarantine zones in Perth for the next year-and-a-half. This decision occurs just as experts warn that the shot-hole borer may be reaching a point of containment that is less and less likely. This change from a joint state and federal funding model to solely state-funded initiatives is troubling. In doing so, it jeopardizes the longterm management of the pest.
Expert Opinions on Containment Challenges
Dr. Bruce Webber an ecologist who has studied the shot-hole borer effect. He argued that containment breaches are a foregone conclusion. He noted, “That’s where things fundamentally change, and that’s where the ability to maintain those quarantine zones is diminished, and that’s where the spread starts to happen.”
During his presentation, Dr. Webber stressed that the time to stop pretending we can contain everything is here. “It’s simply going to be a matter of suck it and see, and that’s a pretty scary outcome given we know there are already impacts identified to our native species.” He warned that the long-term impact on native vegetation is still unknown.
Under its new approach, the WA government plans to strengthen deterrence and prevention measures against the pest. Dr. Webber stated, “This change in management certainly doesn’t mean that we give up and go, ‘oh well, it’s just here now.’ It means that if anything, we become more vigilant.”
Concerns from Local Experts
Local stakeholders, such as Jacquie Rusha, who operates a native plant nursery in Bunbury, have sounded the call over the impending ecological catastrophe. They’re concerned about the impact as the beetle expands its range. Drawing on his 30-plus years working at the Leschenault Community Nursery, Rusha underscored the growing need for biosecurity efforts.
She stated, “If we were to come across an infestation here, we would be able to quarantine immediately and find it a lot sooner than we would in the wild.” This feeling highlights the need for preventive action now that the borer’s attack is outpacing the invasion into cities.
Rusha, too, voiced her concerns about the unpredictable effects on Western Australia’s native ecosystem. She remarked, “And to be honest, I think it’s pretty likely that we’ll end up with it here, if it’s not here already.” This perspective aligns with many experts’ fears that the destructive effects observed in Perth could soon replicate throughout Western Australia’s South West region.
Implications for Native Species and Ecosystems
The shot-hole borer poses a significant threat to various Australian native species, including the Moreton Bay fig, marri, and red flowering gum. Dr. Webber stressed that while some impacts have been identified, many remain unknown. “We don’t know the full extent of the species that will be impacted as the borer inevitably spreads out to these native landscapes.”
Now that eradication is impossible, the focus should pivot to preventing the borer from spreading outside of Perth. Dr. Webber highlighted this urgent need: “Now that eradication is off the table, the priority must be stopping the borer from spreading beyond the Perth region.”
Alarm is mounting over possible long-term ecological effects. “We don’t know how this will all end up looking in the end, but we might lose some of those really key species of plants, particularly marri,” Dr. Webber warned.
