South Australians have been asked to keep an eye out for an invasive pest that has the potential to wipe out thousands of street and parkland trees, as well as some crops, if it spreads into the state.
A national plan is being developed to manage the beetle — the polyphagous shot-hole borer — which was detected in Western Australia in 2021 and has spread through trees in the Perth region.
The WA government recently said it would stop trying to eradicate the beetle, which has put authorities in other states on high alert for its presence.
A shot-hole borer is the size of a sesame seed. (ABC News: Kate Forrester)
South Australian Forest Products Association chief executive Nathan Paine said he was disappointed to see authorities “give up” the fight to eradicate a pest that could cause “untold damage across our urban landscapes and across Australia”.
“Once a pest is in the country, we need to work as hard as we can, like we have here in SA with fruit fly, to ensure that pest is eradicated,” Mr Paine said.
He said the state’s pine plantations were not under threat, but Tasmanian bluegum plantations, native forests, street trees and botanic gardens were.
“Adelaide Oval — the Moreton Bay figs — those are the sorts of trees that, if this beetle gets into SA, will be under threat,”
Mr Paine said.
“If we can stop this now in WA before it becomes significant … we need to make this happen.”
There are concerns for thousands of SA’s street and backyard trees. (ABC News: Che Chorley)
Checks in place
South Australia’s Department of Primary Industries (PIRSA) director of plant and invasive species, Nick Secomb, said the borer had the potential to enter the state from WA in timber, mulch or established trees.
He said PIRSA had been monitoring about 500 sites, mainly within metropolitan Adelaide, for signs of the pest.
Nick Secomb says authorities have been looking for signs of borers. (ABC News)
“The real risk for us is that it might get picked and brought here, and so we’ve had movement controls in place for a while now in our plant quarantine standard,” Mr Secomb said.
“Luckily we’ve got that one road in from WA, we’ve got the Ceduna quarantine station, so all those things get checked.”
Mr Secomb said PIRSA would work with local councils and nurseries to help identify signs of the shot-hole borer.
“We’ve been looking for this pest for the last few years, so we have to keep doing that and make sure we don’t have it,”
he said.
There is no known treatment beyond removing infected trees and, along with native and ornamental trees, the borer can affect crops including avocados, pears, apples, macadamia and mango.
Industry under threat
Riverland avocado grower George Loffler said the pest could potentially wipe out SA’s avocado industry.
George Loffler says the pest is not just a problem for growers. (ABC Riverland: Amelia Walters)
“[If it gets here] I don’t really see how we’re going to stop it, and that’s probably one of the scary things,” Mr Loffler said.
“We don’t want pesticides and chemicals affecting our fruit, and it could be a situation where we might have to abandon our harvest if we have to use those options to control the pest.
“Where does that leave us as a business and as a family, and where does it leave everyone else along the supply chain that relies on us for avocado supply?”
He said the pest was a threat to “every single person out there with a backyard” and everyone had a role in keeping it out of SA.
The borer attacks crop trees including avocados, apples, pears, macadamias and mangoes. (ABC Riverland: Amelia Walters)
“I think there’s a lot more damage done to ornamental trees, which is obviously going to have serious impacts on the millions of people living with a house and a backyard that have got certain varieties of trees,”
Mr Loffler said.
“I guess once they’ve finished destroying all those, they’ll come and eat our avocados.”
