Fire ants have been detected for the first time in the Murray Darling Basin, heightening fears for Australia's largest and most complex river system.
Authorities have confirmed a new detection of the exotic super pest at Oakey, west of Toowoomba.
Experts have long feared what could happen if fire ants entered the basin's waterways, given they can form floating rafts with their bodies and harness river flows to invade new areas.
A map of detections, published by the National Fire Ant Eradication Program, puts the Oakey find at the town's army aviation centre, roughly 4km from Oakey Creek.
Oakey Creek is connected to the Condamine River, with the Condamine-Balonne rivers catchment one of the largest in the basin.
New "outlier detections" have also recently been reported at Caboolture, halfway between Brisbane and the Sunshine Coast, and on Coochiemudlo, Russell and Macleay islands, off Brisbane.
News of the pest's ongoing spread comes a day after a federal parliamentary inquiry published its report on the nation's long-running fire ant eradication efforts.
The report said efforts to stamp out the pest had been hampered by problems including stop-start funding, a lack of transparency and too much bureaucracy.
It warned Australia could face annual losses of $2 billion if the pest escapes Queensland's southeast corner and becomes entrenched.
Nationals leader David Littleproud said the find was extremely concerning, given warnings the hyper-aggressive, swarming pest could reduce agricultural output by up to 40 per cent.
He said any spread throughout the basin would be devastating for the country.
"Labor now needs to urgently respond to the inquiry," he said.
The parliamentary inquiry called for a rapid review to determine if $1.28 billion - committed by federal, state and territory governments to 2027 - is enough, and if not, to come up with a new figure.
The Invasive Species Council says the Oakey detection makes that review even more urgent.
"This new detection outside the fire ant eradication zone and within the Murray-Darling Basin catchment should mean alarm bells are ringing loudly in the prime minister's office," fire ants campaigner Reece Pianta said.
"In recent months we have had new fire ant detections in NSW, at Caboolture north of Brisbane and now west of the Great Dividing Range at Oakey.
"It is now undeniable that there is not enough money to get the eradication job done."
The federal Labor government has told AAP many of the problems identified by the inquiry can be sheeted home to years when the coalition was in power.
