• A shot-hole borer.

THE nasty tree-killing polyphagous shot-hole borer has been spotted in Hyde Park, infesting at least five trees so far.

The mysterious insect’s origin was unknown but it was first identified attacking Sri Lankan tea plantations in 1868.

WA kept the tiny bug out of our borders for a long while but it was first reported in East Fremantle in August 2021 when resident Joanne Taggart spotted unusual insect damage in branches that’d come down in a storm. 

It sent government biosecurity agencies onto high alert and they removed the box maple tree right down to its roots, but sightings of the bug quickly popped up in neighbouring suburbs. 

The “polyphagous” part of their name means they chew into almost any tree, eating their way in and farming fungus for food. 

Their favourite fungus food Fusarium causes dieback and tree death in susceptible species, and the WA agriculture department fears if the pest gets a foothold it’ll be bad news for native vegetation, amenity trees and the fruit and nut industry.

Hyde Park’s infested trees will have their insect-ridden limbs pruned in hopes the body can be saved.

With the bug’s telltale tiny holes spotted in Hyde Park’s trees the ag department will prune branches from five affected trees, and traps have been set up to see if there’s more shot-hole borers flying around and trying to spread.

Hyde Park has many trees listed as “high risk” by the ag department, as they’re particularly susceptible to being turned into fusarium farms by the shot-hole borer, including plane trees, oaks, jacarandas.

As the bug has spread, a quarantine area has been declared across 17 local government areas stretching from the northern edge of Stirling, down to Cockburn, and from the coast to Canning. No wood can leave the area unless it’s been chipped down to pieces less than an inch across, and living plants can’t be moved unless their stems are less than 2cm.

The department’s calling for anyone who spots the shot-borer or its tiny bore holes to call 9368 3080 or use the MyPestGuide app to report, as Ms Taggart did back in August.

The borer, scientific name euwallacea fornicatus, is just 2mm across, shiny, black, and has a big rounded head. 

by DAVID BELL