South Asia’s Euwallacea fornicates (PSHB), the runt of the beetle world, is threatening Australia’s native tree population, causing Australia’s peak body for forest products, the Australian Forest Products Association, to call for the Commonwealth and all State Governments to take action immediately.
“Without jurisdictions committing to a properly funded and coordinated approach to eradicate the PSHB, there’s a serious risk the pest could spread across Australia and seriously impact not only the forestry industry, but also suburban trees across parkland, backyards and reserves, as well as other forests and national parks,” said Diana Hallam, CEO of Australian Forest Products Association.
Wood Central understands that the PSHB – first detected in WA in 2021 – is spreading through backyards, urban forests and native reserves across metropolitan Perth, and is rapidly killing trees. And because of this, eradication and containment efforts need to be increased, or it’s a matter of time before it moves south of Perth to the state’s production forests, or potentially nationwide, killing many iconic trees, decimating Australian backyards and impacting forestry.
“This is not just WA’s problem, and we’re acutely aware that measures to eradicate PSHB through the national emergency plant pest arrangements haven’t been sufficient,” Hallam said last month. “If governments fail to up the ante and act decisively now, we risk setting a dangerous precedent. The cost of inaction won’t just be measured in trees lost, but also damage to ecosystems, biodiversity, communities and our ability to respond to future crises.”
“Our sector feels particularly exposed as our second most important plantation species, the Tasmanian blue gum (Eucalyptus globulus), is susceptible to infestation and a reproductive host. Should the PSHB spread to plantation areas, it would jeopardise a significant segment of Australia’s sustainable $24 billion forestry and manufacturing industry and the 180,000 direct and indirect jobs that rely on it.”
Diana Hallam, CEO of the Australian Forest Products Association.
For Hallam, failure to act decisively now risks setting a dangerous precedent: “that environmental biosecurity threats can be ignored and will be rightly seen by many as dereliction of the shared responsibility of governments across Australia to protect our unique environment and essential industry,” Hallam said. “As with current efforts to control Red Imported Fire Ant in Queensland, a shared-national response is appropriate.”
“Without eradication or effective containment in the long term, Australia’s efforts to preserve biodiversity, provide locally sourced timber and wood fibre for sovereign capability, increase carbon capture and grow our urban canopies will be undermined by this insidious pest.”
The damage caused by the beetle (to date) could have been much, much worse…
Last year, Wood Central’s Jim Bowden exclusively revealed that the PSHB had bit off more than it could chew with regards to West Australia sawn timber. A red alert among Australia’s wood processors came after the tiny, sesame seed-sized pest borer that has caused a $28 billion economic headache in South Africa, was discovered killing trees across Perth.
The good news? The bug dies when transferred from a tree to processed wood.
“What a relief,” said Jack Norton, national secretary of the Timber Preservers Association of Australia at the time.
“Leading entomologists have confirmed what we believed – this borer attacks only living trees. Once it hits sawn timber, it’s hasta la vista, baby.
“At worst, you might see some trails and holes left in the timber by the beetle, but this will have absolutely no affect on structural wood.”
Jack Norton, National Secetary of the Timber Preservers Association of Australia.
Dr Helen Nahrung an entomologist at the University of the Sunshine Coast, with more than 20 years’ experience in insect biology, and Chris Fitzgerald, forest products technologist at the Department Agriculture and Fisheries, agred: “The shothole borer has only been located in Western Australia at this stage,” Fitzgerald said. “It’s one of the few ‘ambrosia beetles’ that feed on a cultivated fungus rather than the wood itself. They will attack healthy trees, especially stressed or damaged trees such as those windthrown or fire damaged.”
Mr Fitzgerald added: “I would think the potential impact would be serious if it were to get into Queensland. There are government control orders in place to help prevent their entry including fumigation or heat treatment.”
Norton said these facts were comfortable truths for processed wood … “but we should not overlook the horrible damage that might further affect our healthy trees.”
The borers are barely two millimetres long, but they can kill a tree within two years.
Wood Central understands that the borers tunnel deep into the wood and cultivate a fungus that blocks the tree’s arteries or vascular system. The tree can’t transport water and nutrients to its branches, and then dies of thirst.
Hundreds of trees across Perth have already been attacked, with stump grinders turning badly infested Moreton Bay fig trees at iconic Kings Park into wood chips and dust. “That’s because for the time being, the only option is to cut down host trees to kill the bug and stop its spread,” a Perth city official said last year.
“The borer is currently contained in the Perth metropolitan area, with states and territories working together to stop it from crossing the Nullarbor and invading the rest of the country.”
Scientists also warn the borers could wreak havoc on crops and decimate urban tree canopies, including the much-loved Port Jackson and Moreton Bay fig trees in Sydney, Brisbane and across the eastern seaboard.
“There will be very few people in Australia who aren’t affected by this beetle,” said Theo Evans, associate professor of applied entomology at the University of Western Australia. Professor Evans said, “Urban canopies, which are already small, will get smaller. That means our summer temperatures are going to get higher.”
The borer is native to Southeast Asia and has also spread to California, Israel, Argentina, and South Africa.
A study at South Africa’s Stellenbosch University estimates the economic impact at $28 billion over the next decade. The shot-hole borer was first detected in Perth in 2021 after infesting two box elder maple trees in an east Fremantle home.
Since then, WA’s Department of Primary Industries and Regional Development has spearheaded a $41 million, three-year national response inspecting more than 1.6 million trees and identifying 1000 infested sites within the Perth quarantine area.
In an ABC report last year, Dr Vincent Lanoiselet, chief plant biosecurity officer at the department, explained the shot-hole borer targeted more than 300 species of mainly non-native trees; hence the term polyphagous – meaning it can feed on many types of a tree’s wood, such as box elder maples were its clear a favourite … “like chocolate for the beetle”.
The highest concentrations of the borer are along the Swan River, in some of the city’s leafiest suburbs. At Lake Claremont, eight heavily infested Moreton Bay figs have already been cut down, and 42 more trees, including a 300-year-old pre-European colonisation paperbark tree, are earmarked for removal.
