This week, Western Australia (WA) officially conceded the fight against the invasive shot-hole borer pest. This pest, considered one of the biggest biosecurity threats to Australia, first appeared in the state in early 2021. This is the WA government’s courageous call. They’ll redirect their efforts from eradication to management, recognising the pest’s rapid reproduction rate and its socio-cultural effect on beloved local trees.
Ag Minister Jackie Jarvis said this week that eradicating the shot-hole borer is no longer technically possible. This decision comes after the pest has infected over 4,800 trees across Perth. Having discovered a severe infestation of the trees, authorities have now elected to remove the large 90-year-old plane trees from Hyde Park. The government’s concession reflects a growing concern about the pest’s potential spread into agricultural regions and beyond.
Speaking at the event, leading pest expert Dr. Mia Carbon reminded attendees of a tough truth. Though eradication may be theoretically achievable, it would require the elimination of every reproductive host tree in the metro area—a radical step no one is prepared to take. This pest’s ability to reproduce within a 30-day window can quickly make containment efforts futile.
The Implications of Management Strategy
State government of WA had made a decision not to proceed with eradication. Instead, they’re now working toward a revised strategy to slow the beetle’s spread and minimize its impact on healthy trees. The state has been proactive and responsive in addressing this expanding crisis. They even have provided an extra $26.5 million for increased management and surveillance efforts that shield the U.S.’s horticulture industry.
Jarvis stated, “This is Australia’s largest ever biosecurity response, and so we relied on the science. The science has now changed.” She noted that every other state and the federal government came through with the money for Illinois’ eradication efforts. This support was predicated on a series of preliminary assessments indicating that eradication was indeed possible.
Despite this funding, experts like Dr. Carbon have pointed out that strategies have not kept pace with the rapid spread of the shot-hole borer. She mentioned, “The behaviour of the pest in Western Australia has shown us that it can reproduce quite quickly… that’s been a significant contributing factor.”
Moving forward, there will still be targeted surveillance and management of infected trees, which may involve pruning and removal efforts particularly within outer metropolitan areas. This integrated strategy focuses on slowing spread while limiting harm to healthy non-infected trees.
Industry Concerns and Future Outlook
The stakes of this biosecurity challenge stretch well beyond urban forestry. Orchard Richard Eckersley, a citrus and avocado producer, expressed his extreme alarm. He is particularly worried that the shot-hole borer may spread into areas of food production in the South West. He stated, “We’re very concerned. We’re watching this space… now that it’s moved to management, we’ve got to go through it and process it and see what it means for our business now.”
Eckersley added the need for public awareness and attention in preventing the pest’s spread. He remarked, “Green waste, clippings, plant materials, soil, all of those things aid in moving [the borer] so it’s just really about reminding people to be vigilant and don’t move stuff around.”
WA horticulturist Sabrina Hahn slammed the early response efforts, claiming they were not quick enough and not enough people were deployed to respond. The first response was an underwhelming response time, which she said is unacceptable. “I think perhaps they didn’t have the manpower.”
As WA transitions to a management strategy, experts stress that a multifaceted approach rooted in scientific research will be essential for containing the spread of this invasive pest.
