Help protect trees against spread of plant pest Shot-Hole Borer

Native to Southeast Asia, the PSHB (Euwallacea fornicatus) is known to have attacked over 500 plant species globally including in the United States, Israel, and South Africa.  

The tiny beetle was first detected in Perth in 2021. Since then, thousands of trees have been infested by the PSHB, including iconic Moreton Bay Figs in Kings Park and Botanic Garden. It’s still unknown how and when it entered Australia. 

Chief Scientist at Botanic Gardens of Sydney, Professor Brett Summerell AM, said the tiny beetle carries a deadly fungus that kills trees by blocking their water and nutrient pathways. 

“The impact in Perth has been enormous—over 3,800 trees removed, millions spent on surveillance, and a significant loss to the city’s green canopy.” 

“Its partnership with a Fusarium fungus makes it particularly lethal. While the beetle alone causes moderate damage, the fungus it introduces into trees can lead to widespread devastation,” Professor Summerell said. 
 

In June, the National Management Group agreed that it was no longer technically feasible to eradicate the pest from WA, and it would instead focus on limiting its spread.  

Botanic Gardens of Sydney and the Department of Primary Industries and Regional Development (DPIRD) have been proactively monitoring for the pest, which spreads with the movement of infested wood, firewood and green waste material.  

Moreton Bay figs (Ficus macrophylla) and Port Jackson figs (Ficus rubiginosa) have been identified as preferred breeding hosts for the tiny beetle – two species which are commonly found in parks, gardens and streets across Sydney. 

Pheromone traps have been placed at key sites, and highly skilled arborists are regularly inspecting vulnerable tree species. A recent detection by NSW DPIRD of a related species, the Tea Shot-Hole Borer, was quickly identified and contained. 

Discussions are also underway with other agencies, such as Greater Sydney Parklands and City of Sydney to help develop strategies for surveillance and management.  

“Once established, the beetle can spread rapidly—flying short distances of up to 400 metres at a time – but movement of infested wood, mulch and living trees is the major concern,” warned Prof Summerell.  

“If it arrives in Sydney, it could have devastating consequences for our urban forest and the living collections in our Gardens.” 

Capabilities at PlantClinic, which offers plant disease diagnostics at the Royal Botanic Garden, are being expanded to ensure rapid identification and response to any incursions.  

Professor Summerell said the public can play a vital role in early detection. 

“The first Perth sighting occurred in a home garden, highlighting the importance of community vigilance.”  

• Keep an eye on fig, plane, and box elder trees in your area.
• Check trees for signs of borer damage and wilting.
• Report any unusual signs of tree stress or beetle activity by calling the Exotic Plant Pest hotline on 1800 084 881 

Symptoms of borer damage could include: 

• Multiple entrance holes on the trunk or branches that are up to 2mm or the size of the tip on a ballpoint pen.
• Frass extruding from the tree and crystalline foam which looks like sugar volcanoes exuding from the entry holes.
• Thick resin or sap on the tree’s branches or trunk.
• Dark brown to black staining of the wood around entrance holes.
• Wilting and dying branches and eventually tree death. Symptoms usually start in the upper canopy.