Red imported fire ants are a ‘super pest’ that could cost the Australian economy more than $1.5 billion each year – nearly double all of Australia’s worst invasive species, combined.

Biosecurity Queensland lead scientist Dr Ross Wylie said it’s a figure that makes the ant one of the most feared and destructive species to have landed on Australia’s shores.

“The red imported fire ant, its name is Solenopsis invicta and ‘invicta’ means unconquered,” said Dr Wylie.

“It’s probably one of the world’s most invasive pests and certainly the most invasive ant species in the world,” he said.

The first fire ants were detected in Brisbane in 2001.

Their discovery had federal and state governments declare a ‘national emergency’ as they scrambled to reform biosecurity laws and launch a $123 million five-year program to stamp out the ant.

But twenty years on, the ants still haven’t been eradicated.

What if we lose the war?

Invasive Species Council CEO Andrew Cox said a widespread fire ant invasion would be a disaster for Australia’s wildlife, farmers, and the Australian outdoor way of life.

“[Fire ants] overwhelm all the insect life in the area, they can attack small birds… they make farms unsafe places for workers, they can attack newly born calves,” said Mr Cox.

“Grassy areas that we can sit down on without getting bitten, they change that, because fire ants when disturbed will rapidly attack any person that comes nearby.”

“Only if you’ve had to live with the fire ants, do you understand why they’re such a bad thing”.

Last month, a fire ant outbreak in Yarrabilba, Logan, forced football fields to shut and left dozens of homeowners and children stung.

One Yarrabilba women Casey Rixon had armed herself with a can of fly spray after fire ants invaded her garden and began swarming along her garage door.

“I had to open the garage manually and they fell all over me,” she said.

“I contacted Biosecurity [Queensland] and they turned up about 4 days later, put something down the hole of the nest and marked it pink.”

Mrs Rixon said she had seen no fire ants since the treatment but warned Brisbane homeowners to be careful.

“Watch for any mounds in your garden, watch yourself and kids, and do some research especially if you suffer from severe allergic reactions or anaphylaxis,” she said.

Last-ditch effort: a new eradication program

Biosecurity Queensland launched a new $411.4 million fire ant eradication program in 2017 after an independent review found it was still possible to eradicate the ant.

The program outlined a ten-year plan to gradually eradicate the ants, beginning with colonies in the Lockyer Valley and moving east towards Brisbane.

Meanwhile, communities waiting for full eradication treatment were asked to report fire ant sightings and given baits from Biosecurity Queensland to keep the ants from spreading further.

Dr Wylie said the strategy seemed to be working.

“In some of the areas where full-blown eradication is going on, people haven’t been seeing fire ants for a while, whereas they were quite common previously.”

“We’ve already covered perhaps 250,000 hectares with a tremendous reduction of what was in those areas.”

In Australia, fire ants have spread at a rate of 4.8 kilometres each year since 2001, compared to an estimated 48 kilometres per year in the southern United States and 80 kilometres in China.

Sean Hodge, who conducted surveillance last year in the Lockyer Valley’s Laidley region, agreed the program seemed to be “fairly effective” but said not all properties were receiving full treatment.

“Several times we’ve found ants where there shouldn’t have been ants anymore,” he said.

Mr Hodge said those nests tended to occur near properties that his team had not been able to access for surveillance or treatment.

“It comes down to management – we’re meant to have the authority to go onto any property no matter what,” he said.

“When landowners or farmers reject us and reject us, the idea is that it gets raised up to management and eventually if they keep refusing, we turn up with the police in tow to let us on and treat the property.”

“If you’re not doing that then you’re not going to get 100 percent coverage and you’ll have these nests pop up, and next thing you know, these things spread like wildfire,” he said.

The detection problem: 'you can't say that the ants aren't there'

Dr Wylie said knowing whether treatments had worked was the biggest challenge facing the eradication program.

“You can’t say that the ants aren’t there, all you can say is that we didn’t find them,” he said.

“You may not see any evidence of an ant at all for five months, yet the ant is there.”

Fire ants are easiest to detect in the winter months as they build their nests, but in summer, the ants tend to stay underground.

Dr Wylie said fire ant baits can also take up to two years and six treatments to kill off a persistent colony.

“I can think of 14 different reasons why a fire ant may not take a bait we put out,” said Dr Wylie.

“It might be too hot, too cold; they might have already eaten; a cow might have put a foot through the nest and they’re too busy rebuilding.”

A spokesperson from the National Red Imported Fire Ant Eradication Program said fire ant surveillance will be undertaken over a number of years before they can confidently say fire ants are no longer present.

The program can declare an area ‘fire-ant free’ only if the community, professional teams, sniffer dogs and remote-sensing helicopters find no new nests after two rounds of surveillance over two years.

The invasives of the future

Invasive Species Council CEO Andrew Cox said fire ants aren’t the only small invasives that can slip past Australia’s border control and cause a biosecurity disaster.

“Any day now we could have a new ‘fire ant’-type ant species, a new ‘super plant’ weed come to Australia, and we would have more extinctions than we are currently already facing,” Mr Cox said.

“Some of the big obvious animals we’re getting better at keeping out, but the smaller stowaways like the red fire ants, like all the bugs that might be in your packaging that you bought over eBay, are becoming more of a problem.”

Mr Cox said the pressure for importers to check goods cheaper and faster is a recipe for poor biosecurity practices, quarantine measures and apathy towards keeping imports free of pests and diseases.

“The rate of arrivals isn’t going lower, it’s getting higher. The risk is getting greater,” he said.

“Things are probably getting worse before they’re getting better.”

Former Queensland Farmers’ Federation President Stuart Armitage said the fire ant eradication program relies on everyone doing their part in reporting suspect ants and nests.

“A lot of people seem to think that biosecurity is just a problem for agriculture – it’s not. Everyone has a role to play and a general biosecurity obligation.”

“Australia is the closest any country has come to eradicating fire ants, and if any state can do it, Queensland can.”