Hardly a 'boring' topic

Horticulturist Jonathan Garner warns everyone to be prepared for an infestation making its way to the eastern states.

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Polyphagous Shot Hole Borer (PSHB) is a tiny invasive critter from Southeast Asia that was detected in a Perth suburb in August 2021.

Since then, PSHB has established itself in the Perth metropolitan area, and like recent arrivals such as the Varroa mite in NSW and fire ants in southeast Queensland, eradication of PSHB has proven impossible. There is no effective chemical or biological control. Authorities have shifted to a long-term management approach rather than trying to eliminate the beetle.

Now it has established a foothold on our island, it's only a matter of time before PSHB spreads further through Western Australia and eventually the east coast, driven by road-trip tourism and long-haul freight of nursery plants and wood products. Currently, the entire Perth metropolitan area of 630,000 hectares is under quarantine, with the outlying suburbs deemed containment areas. Despite the area being small at present, it doesn't take much for the beetle to spread.

Who knows? It might be in your landscape asset already

What is it and what does it do?

PSHB is a small, wood-boring beetle native to Southeast Asia. Adult beetles are tiny, around 1-2 mm long, making them difficult to spot without close inspection. The kicker with this pest is the relationship it has with a deadly fungus called Fusarium wilt. In fact, Fusarium wilt is both the beetle's food source and the killer of woody trees and shrubs.

Understanding PSHB's rapid and efficient breeding cycle is both intriguing (due to the fungal relationship) and concerning (due to how destructive the relationship is). It demonstrates how successful this duo will be at destroying trees and possibly forests. Here's a snapshot of its breeding cycle: