It is a cool autumn morning in north-east Victoria, but already there are European wasps trying to get into the shops.
"They can be absolutely shocking some days," said Janet Martin, the manager of the Beechworth Bakery in Yackandandah.
Last week a staff member and a young customer were stung.
"Because [the wasps] are meat eaters, they're eating the dead insects off the cars," Ms Martin said.
"So on the hot days when they're swarming, you're getting a mass of them because the cars are parked … nose in at the bakery."
She has put up warning signs this year and an insect sprayer over the outdoor tables, but she wonders if the wasps are having an impact on tourism.
"Is it putting people off?" Ms Martin said.
"Is it stopping people from sitting here and enjoying their cup of coffee because the wasps are hanging around?"
The war on wasps
European wasps first came to the mainland in the 1970s and had spread across Victoria by the 1990s, according to Agriculture Victoria.
Yackandandah local Neil Padbury has been fighting them ever since.
"When I was trying to make salamis and things and hanging those in the shed, the wasps would come and eat them," he remembers.
"So I needed to work out … how to find nests and how to attract wasps and how to deal with their nests and keep the numbers to a minimum."
Mr Padbury formed a community group that became a subcommittee of the Indigo Shire Council.
In 2016, there were efforts to remove wasps before the Yackandandah Folk Festival.
In 2017, wasp control options – and their impact on tourists – were on the agenda at council meetings.
"So we did a lot of experiments and got some different sorts of treatments to see what worked and what didn't work," Mr Padbury said.
"Turns out that most of them don't work very well, and so the problem is still here."
Hunting the crown
What Mr Padbury has found effective is baiting in springtime to catch queens before they form nests.
He has got fellow members of the Men's Shed on board, but the wasp subcommittee has petered out.
The Ovens Landcare Network has also been running a subsidised baiting program in the area since 2020 thanks to funds from local government and bank grants, but project coordinator Gayle South says that is about to wind up too.
"Our funding and our supplies have been almost exhausted," she said.
"I think there's over 1,000 traps that we've distributed in the area, and about 2,500 lures — so, substantial numbers that we've got out there."
Ms South is worried about the impact on the ecosystem.
"Their diet consists of insects, and we're quite concerned that many of these insects are our pollinating insects," she said.
Off with their heads
University of Sydney senior lecturer in life and environmental sciences Thomas Newsome says there are more European wasps around this autumn than he has seen since 2018.
"Even over the last two to three weeks I've had two separate inquiries from local land services and pest land managers who have noticed increases in European wasps this year," he said.
Dr Newsome puts that down to dry conditions.
"Many of the European wasps nest underground and so during those wet years, they either get flooded, or they get inundated with water," he said.
Despite the major flooding Victoria saw back in spring, summer rainfall was below average, according to the Bureau of Meteorology.
In Dr Newsome's studies in Kosciuszko National Park, he has observed wasps deterring larger scavengers like dingoes and taking out smaller competitors for carcasses.
"When a fly would come in, they would physically grab the fly," he said.
"And then, with their sharp pincers, or whatever they're using, they essentially decapitated that fly."
Dr Newsome said there was a lot of interest in the effect wasps had on people, but their ecological effects were "completely underestimated" and hard to document.
He wants to see more studies of targeted baits and the wasps' impact, and is encouraging people to avoid providing outdoor meat sources.
"I think they've really flown under the radar as an invasive pest," Dr Newsome said.
"Wasps are highly territorial — they're very aggressive and they can sting multiple times and a lot of our native insects don't have any real defences against that.
"So European wasps have a major advantage in terms of their ability to outcompete native insects."
