A new nest of red imported fire ants was detected at the original infestation site very close to the Queensland border on Thursday.
Today the National Fire Ant Eradication Program revealed it was working with the NSW Department of Primary Industries after a new report of RIFA in at South Murwillumbah.
A NFAEP spokesperson confirmed on May 9 one fire ant nest was found and treated on the same South Murwillumbah development site where the pest was detected on in November 2023.
"The development site, and up to 5km of the surrounding area is currently subject to fire ant eradication activities," the spokesperson said.
"It is not uncommon to find fire ant nests in areas receiving eradication treatment."
The spokesperson said eradication was a multi-stage process using an insect growth regulator that prevents the queen from producing viable and reproductive offspring.
"This treatment takes effect over several weeks," the spokesperson said.
"All properties in the targeted area must receive multiple rounds of broadscale treatment over two years to ensure eradication success.
"One round of treatment has been applied to 500m out from the original detection and round two started last month.
"The nest has been treated by direct nest injection and samples of the ants to help determine if the ants are related to the original cluster.
"The program's initial assessment indicates the nest found is not reproductive."
Mayor of Tweed Shire Chris Cherry said the detection of a new RIFA nest at the original site of infestation underscored the importance of remaining on guard.
"We are once again grateful for the ongoing vigilance of our contractors, the NSW DPI and the NFAEP teams who are monitoring this site at South Murwillumbah and detected this new incursion," Cr Cherry said.
"While this new discovery was not unexpected, it is a reminder that the problem of fire ants remains with us in the Tweed.
"We cannot afford to let our defences down - it is vital all landowners continue to work with the responsible jurisdictions and allow consent for ongoing treatment on their land."
The site will continue to be monitored by the NFAEP, NSW Government and council staff and residents and businesses are urged to report any suspicious ant activity to 1800 680 244.
