NEWS the coordinated response to the polyphagous shot hole borer (PSHB) has now officially moved from an eradication phase to long-term management marks a critical turning point for the region and the natural environment, according to the Shire of Mundaring.

On June 19 the Cook Government said the national management group (NMG) had met and determined it was no longer technically feasible to eradicate shot hole borer from WA, after considering the latest scientific data and advice from the country’s chief plant health managers and leading plant biosecurity experts.

Agriculture and Food Minister Jackie Jarvis said a new national transition to management plan would be finalised.

The Department of Primary Industries and Regional Development (DPIRD) will continue as the key agency in Western Australia.

The government’s announcement came the day before PSHB gets a foothold in Kalamunda and Swan (Echo News, June 20) reported the cities of Kalamunda and Swan had both lost trees to the invasive beetle, first detected in WA in 2021.

In the story the City of Kalamunda said the number of infected trees for removal (or removed already) was 52 and  the City of Swan said it had lost a small number of trees but did not disclose an exact number of trees that had either been removed or were set for removal.

The Shire of Mundaring said the shire had not been advised of any confirmed PSHB tree infestations within its local government area.

When news of the decision to move from an eradication phase broke Mundaring President Paige McNeil said it put the Perth Hills’ biodiverse environment at a critical crossroad.

“This confirmation is especially concerning for (the shire), as we are the environmental stewards of a vast region of mature forest and an internationally recognised biodiversity hotspot already under considerable ecological pressure from recent bushfires and the 2023-24 summer drought,’’ she said.

“So far, we’ve been lucky no infestations have been confirmed within our shire. “However, we recognise and support the continued efforts of DPIRD and urge residents to remain alert to signs of the borer so we can all contribute to protecting our local environment.’’

The Invasive Species Council policy director Carol Booth said the news was potentially tragic, not just for native trees and horticultural industry in WA but all across the country.

“Fifteen native tree species in WA have already been identified as highly or very highly susceptible to the polyphagous shot hole borer – including iconic species like paperbarks, banksias and eucalypts,’’ Dr Booth said.

“It implies hundreds of native species across the country could be at risk if the borer spreads.

“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.

“We need coordinated efforts and strong containment measures in place to protect forests, bushland and urban trees across the rest of Australia.”

Dr Booth said substantial funding needed to be dedicated to investigating and managing the potential environmental impacts – not just the risks to horticulture industries.

DPIRD deputy director general Mia Carbon said the NMG determined eradication could no longer be achieved due to a number of factors.

“Determining factors included the difficulty in detecting and controlling new borer infestations at an early stage before the pest can reproduce, and the current lack of effective chemical treatments available for killing the borer,” Dr Carbon said.

“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.”

Dr Carbon said DPIRD would lead the transition to management in WA to minimise the impact of PSHB on Perth’s tree canopy and help protect the state’s horticultural industries.

“Over the next 18 months, DPIRD will work with industry, community and local government to build skills, knowledge and capacity to manage the pest long term.”

WALGA President Karen Chappel said Ms Jarvis’ decision was a result of the inadequacy of the state government’s early response to PSHB.

“WALGA has long been concerned about the effectiveness of the state’s PSHB response and has been calling for greater transparency, research into control methods and more community education and engagement,” she said.

Cr Chappel said it would have significant implications for local government, who were already spending millions to control PSHB and increase tree canopy.