Fresh warning on fire ants in Queensland as suppression efforts struggle to halt spread | Invasive species

Parts of Queensland have as many fire ants as Texas – a hotbed of the uncontrolled infestation that costs the US billions of dollars each year, an expert has warned

Dr Robert Puckett is an American specialist on invasive ant species and he’s followed Australia’s efforts to eradicate fire ants since they were discovered in Brisbane 23 years ago.

Puckett has just toured infested parts of south-east Queensland and has echoed stories from locals about a shocking buildup of the super-pest inside the narrow, U-shaped band where eradication efforts are focused.

“Some of the densities are approaching what we see in Texas on pasture land,” said the entomologist, from Texas A&M University.

“The higher the density inside the suppression zone, the greater the risk ants could be moved out, across the eradication band, and be deposited elsewhere in Australia.”

The observation is no surprise to Stuart Webber who volunteers his time treating thousands of fire ant nests in the Logan area, south of Brisbane.

Webber is most worried about the high-density infestations he keeps finding along the Logan and Albert rivers as fire ants can use their bodies to form floating rafts and invade new areas.

A couple of months ago, at a riverside property at Waterford, he spent 30 hours treating more than 2000 nests, but reckons that was only half of them.

“I worry about the next flood. This is the panic I’ve got,” he told AAP.

Australia has just poured hundreds of millions of dollars of extra cash into its war on fire ants but even so, what’s being spent is a drop in the bucket compared to what annual expenses will be if the battle is lost.

Fire ants attack crops and livestock, driving down agricultural productivity. They swarm and kill native species. They push up health care costs as medics treat painful stings that sometimes kill.

They eat electrical infrastructure, and can render back yards and sports grounds useless without ongoing treatment to keep them at bay.

Biosecurity analysts told a recent Senate inquiry that Australia could lose 2.8% of its GDP to fire ants – an economic hit equivalent to “half a Covid” each and every year.

The Invasive Species Council has long been worried about rising densities in the suppression area ringed by the active eradication zone.

It’s a vast swathe of the south-east covering Brisbane, Ipswich, the Gold Coast and extends west to Gatton. Many of those locations won’t see active eradication for some time.

Reece Pianta is the council’s fire ant specialist and he is unsurprised by reports of thousands of nests on some properties.

He said suppression is not part of the national eradication program and is instead managed by the Queensland government’s complementary Fire Ant Suppression taskforce.

It provides free baits but the onus is on property owners, tenants and farmers to source and apply it.

Webber said it’s obvious – based on the volume of nests in his area – that people aren’t doing that at anywhere near the scale required to keep ant numbers in check.

He said he recently went to another property near his home that had about 1000 nests – and that’s not unusual, especially in horse paddocks.

The Invasive Species Council is keen for authorities to take a fresh look at the adequacy of suppression efforts and believes it should be a core function of the eradication program.

“This is for the benefit of the whole country. Suppression is a fundamental part of successful eradication,” Pianta said.

The National Fire Ant Eradication Program said local, state and federal governments are already treating fire ants on land they own and manage in the suppression area.

From next month, people in Ipswich, Logan and select suburbs in Brisbane and the Gold Coast can order a free treatment kit to manage fire ants on their land.

Treatment will be sent twice a year in a bid to keep fire ant numbers down.