What do the scientists say about the fire ants at Wardell? Will they spread?

How worried should we be?

Originally from South America, the fire ants are considered one of the world’s most invasive pests.

At a community meeting last month hosted by the Department of Primary Industries, about 35 people came to Wardell Memorial Hall with questions. The village is under a fire ant biosecurity Emergency Order extending in a 5km radius of Wardell.

The cluster of five nests in a 60m area was discovered by a gardener at Wardell Pod Village on January 19. The cluster counts as one infestation. The fire ants like disturbed soil and because of landscaping work, the ants could have been brought in through mulch, soil or some other way.

So, what does this infestation discovery mean for Wardell and the Northern Rivers and is there any way to stop it getting worse?

Answering fire ant questions at the community meeting were two men – NSW Department of Primary Industries chief invasive species officer Scott Charlton and the National Fire Eradication Program chief operation officer Graeme Dudgeon.

As of today, February 1 there have been no new fire ant infestations discovered in Wardell and surrounds. The Emergency Order and 5km exclusion zone remains in place.

Mr Charlton said it could be up to two years before Wardell has its Proof of Freedom papers and is free of fire ants.

“No one in southeast Queensland has been cleared,” he said.

“The metric for success is stopping the spread.

“The ants are difficult to get rid of.”

Sniffer dogs, drones and helicopter spraying are part of the approach to stop the fire ant spread.

So too, is consultation with the community on eradication and educating residents on on how to spot a nest.

Mr Dudgeon said a typical sign to look for was there was no obvious entry to a fire ant nest.

Typically, fire ants don’t seem to like natural bushland.

“They like to nest along curbs and guttering.”

What happened on January 19?

The infestation was confirmed at 4pm, Mr Dudgeon said.

Ballina Council secured the site. The infestation was treated by injecting the nest with the chemical Fipronial.

The nest in Wardell is “likely” to be linked to Queensland but Mr Dudgeon said they were waiting on genetic testing to confirm this.

We use the pheromones of the ant to train detection dogs. They don’t look for nests, the dogs smell them, Mr Charlton said.

“We will use helicopter baiting in cane fields. We don’t do rooftops or houses.”

What is the fire ant bait made of?

The fire ant bait is made up of corn grit soaked in a mixture of soybean oil and Insect Growth Regulator.

IGR is either S-methoprene or pyriproxyfen. S-methoprene is widely used in mosquito control programs, and pyriproxyfen is commonly used in dog and cat flea collars.

The bait treatment is used according to the product label and permit from the Australian Pesticides and Veterinary Medicine Authority to ensure safety to humans, animals and the environment.

The aim is make the queen infertile and then the nest dies of old age.

Sometimes the baiting is done six times to make sure we get rid of every queen out there, Mr Charlton said.

What about the cane harvest in June–July? Will it interrupt that?

The trash from the harvest is the biggest risk.

“We won’t interrupt normal crushing,” Mr Charlton said.

A farmer asked about ti-tree mulch – “not sure” was the response.

The movement of materials was a major issue for farmers if the fire ants spread.

A Coraki farmer said he wanted to pre-empt an incursion mid-harvest.

“We need that certainty,” he said.

Unfortunately, there seems to be little certainty with fire ants.

Making sure everybody knows

“How will you spread the word to people in town, a farmer asked.

SMS messaging is used to alert people to an immediate threat, Mr Dudgeon said.

And DPI is running a social media campaign.

“Our mission is to get rid of fire ants and lift movement restrictions.”

People can assist with this, he said.

“When you bring material onto your property make sure it is fire ant free.

“Products from Queensland have to be certified.”

What about animals – chickens, bees, dogs?

A resident asked about the impact of baiting on compost, chickens, bees and vegetable gardens. And the impact on other insects.

Mr Charlton said the bait chemical was Commonwealth Government certified.

“It is safe to use if you follow the instructions. It will not impact Australian Organic Certification.”

He gave an example – a dog would have to eat more than their bodyweight for it to affect them.

And what about the natural environment?

“The native ant is the most likely to be impacted but research says native ants are more impacted by the fire ant itself,” Mr Charlton said.

The initial injection of chemicals into the nest disturbs the fire ants. They try to evacuate the queen through side tunnels. This injection kills the ants in 48 hours.

“Baiting is a secondary thing be sure,” Mr Dudgeon said.

“We may decide that it is over the top. It can take two years for full eradication treatment.

“The ants are just so resilient.”

What is being done at the Queensland/NSW border to stop the spread?

“We’re sitting ducks,” a farmer said.

“Are you guys going to stop material coming across the border?”

Mr Charlton said, “We are going to triple our capacity.”

“Stopping trucks is only a small part of this,” Mr Dudgeon said.

Our approach is more broad than road blocks, he said.

“We look at paperwork and do lots of cross-checks.

“We use border cameras and we insist on a record of movement and we use a tracker. It acts as an incentive to do the right thing.”

What about baling in the exclusion zone?

Mr Dudgeon said if a crop is industry baled and kept on a concrete slab,  you’d have to wait eight weeks to meet movement conditions.

What about National Parks?

Mr Charlton said they baited National Parks in Queensland.

“On Stradbroke Island, the community worked hand in hand with us to eradicate ants.”

Mr Dudgeon said it was more likely the ants would be building nests on flat cattle country, not in natural bushland.

Recycling waste and the tip

“We treat recycling waste as a potential site, “ Mr Dudgeon said.

Under the Emergency Order, it and green waste can be taken to the tip as the tip will be baited.

Working with farmers

Mr Charlton and Mr Dudgeon said they will work with farmers and industry.

If an area is sprayed, you shouldn’t mow for 48 hours.

Mowing can disturb the ants and they will move to another place such as a garden bed.

They will be contacting farmers directly in the 5km exclusions zone to discuss baiting. There is no cost to farmers when their property is treated for fire ants.

What can I do?

Anyone who discovers a fire ant nest should call 1800 680 244 immediately. If possible, take a photo or video for confirmation that it is fire ants.

Everyone needs to keep an eye out for nests. And report it straight away.

For information on the movement of material and about fire ants go to the DPI website.

This article appeared on indyNR.com on 1 February 2024.