There are fears the invasive fire ant, which can form a raft to move along waterways, may have spread during record floods in southern Queensland.
The state government said floodwaters moved too fast for the insects, but the opposition has called for evidence the risk had been assessed.
Landholders, meanwhile, said they were worried eradication programs were not moving fast enough.
The tiny pest has the potential for disastrous impact should it move unchecked and experts have warned it could cause billions of dollars of social, economic and environmental damage.
Unseasonal rain earlier this year wreaked havoc in the Lockyer Valley, west of Brisbane, including two major floods only 10 weeks apart.
The movement of such floodwater has LNP's opposition spokesman for agriculture and Gympie MP Tony Perrett worried.
"We just don't need them to be spread any further but more importantly, go undetected," he said.
Often referred to as a super pest, red imported fire ants are renowned for their ability to not only move across the ground and fly, but also to float.
The National Fire Ant Eradication Program identified the insects could raft on water by linking their claws and trapping air under their bodies, allowing them to float in groups and travel long distances on waterways.
Mr Perrett asked the government via a question on notice if it was investigating the risk, and if the ants had spread.
"It's quite clear that they say they have a remarkable ability to be able to survive floods and can float for weeks until they come to dry land or a place where they can rest again," he said.
"So, I am seriously concerned that they have spread and if that's the case, then we need to know that."
Floods 'too fast' for fire ants
In response, Agriculture Minister Mark Furner said he had been advised the floods were too swift to allow the fire ants to raft.
"The information we have at hand is that the 2022 flooding event was a rapid event in terms of rises and the high flow rates, which actually reduced the likelihood of any spread," he said.
But Mr Perrett was not convinced, and called on the minister to provide an update on the state's 10-year eradication program, which is about halfway through.
"It didn't provide a lot of information other than to say, 'Trust me, we believe that we've got this right'," he said.
The National Fire Ant Eradication Program began in 2017 with a $411 million budget from the Commonwealth, states and territories.
It was Australia's largest biosecurity eradication plan.
According to the plan, the current incursion takes in a large area of South East Queensland, stretching across the Lockyer Valley, Scenic Rim, Somerset and Ipswich local government areas.
Landholders question aerial assault
The current eradication program includes deploying chemical insecticide baits from helicopters, but some landholders are worried the technique is not effective and could be affecting their animals.
The owners of a Lockyer Valley horse spelling and agistment farm fear the current control measures are not working fast enough.
Joyce Wilkinson and her partner often keep up to 60 thoroughbred horses on their farm, Atkin Lodge.
They do not want the ants to spread, but worry about the impact of chemicals dropped from helicopters on their horses and would prefer a targeted ground operation.
"To me, that is more of what they should be doing, actively seeking where these nests are," Ms Wilkinson said.
"When they used to do the dogs to identify nests, they could actually treat those individual nests and actually destroy the ants in them."
Ms Wilkinson acknowledged that helicopters with heat-seeking technology were often used to identify the nests because the ants were difficult to see on the ground, but she said the low-flying aircraft impacted her animals and should be used sparingly.
"Their thing is to run away from something that's scaring them, and a fence doesn't always stop them when they're running," she said.
Mr Furner said his government had further strengthened its commitment with a $37.1 million fire ant suppression taskforce in this year's budget.
"Beating the fire ants will be a team effort," he said.
But Mr Perrett said the taskforce's name indicated a shift away from efforts to eradicate.
"We can't afford to lose this battle," he said.
The ABC contacted the National Fire Ant Eradication Program for comment however it declined to respond.
