Red Imported Fire Ant spreads to North Stradbroke Island

A destructive ant species known to kill people and livestock has spread to the Queensland tourism hotspot of North Stradbroke Island.

A destructive and aggressive ant species known to kill people and livestock has spread to the Queensland tourism hotspot of Minjerribah, in a major incursion of a pest the state has been trying to eradicate for decades.

And the spread of the Red Imported Fire Ant to Minjerribah, otherwise known as North Stradbroke Island, could have a “significant impact” on tourism the Invasive Species Council warned.

The National Fire Ant Eradication Program, run out of Queensland, confirmed a fire ant nest was found on the island — which is outside the biosecurity zone — by a member of the public in mid-January 2023

But further surveillance revealed a total of 21 nests spread across three properties in Dunwich, in what is understood be a relatively large incursion considering the ant hasn’t been found there before.

Investigations are ongoing to determine how the ants spread to the island, though the transport of infested materials is the most common way the pest is introduced.

A spokesman for the National Fire Ant Eradication Program said moving “just one fire ant queen to a new area, accidentally or otherwise, could lead to the infestation of an entire community”.

A total of 21 nests have spread across three properties in Dunwich.

Quandamooka Yoolooburrabee Aboriginal Corporation (QYAC) confirmed most of the nests had been found on former sand mining leases and noted it was “extremely concerned” about the significant harm the ants could cause on the island’s ecosystem.

The Red Imported Fire Ant, native to South America, was first detected in Queensland in 2001. Previous estimates have put the ant’s estimated cost to the economy at $1.65bn a year if spread was uncontained.

QYAC’s rangers are working with Biosecurity officers, state government rangers and other specialists to urgently eradicate the ants within a 500-metre perimeter of where they were detected.

QYAC land and sea manager Darren Burns said they had been in discussions with multinational company SIBELCO, which had mined minerals from the sand on Minjerribah until 2019 and had agreed to rehabilitate land over several years.

Invasive Species Council spokesman Reece Pianta said fire ants would have a “significant impact” on Minjerribah’s appeal to tourists if the pest took hold.

“Fire ants found on Minjerribah are a cause for concern – these ants are an aggressive invasive species that impact wildlife, pets and humans,” he said.

“Fire ants have caused over 85 deaths in the United States and billions of dollars in economic costs each year. If left unchecked, fire ants would have spread to most of eastern Australia by now.”

Fire ants are between 2mm to 6mm in length and copper brown in colour with a darker abdomen. Nests appear as mounds or patches of loose soil, though there are no obvious entry or exit holes.