Invasive ants eradicated from Tiritiri Matangi

  • Maggie Barry

An ant considered one of the most destructive invasive species in the world has been successfully eradicated from Tiritiri Matangi Island in the Hauraki Gulf, Conservation Minister Maggie Barry says.

“Tiritiri Matangi is one of the few places in the world where Argentine ants have been successfully eradicated, the culmination of 16 years of hard work by DOC staff and volunteers,” Ms Barry says.

“They may be small, but these ants are one of the most damaging of all invasive pest species. The World Conservation Union lists them as one of the 100 worst eco-invaders on Earth.”

Highly aggressive, Argentine ants can form massive super-colonies with a huge appetite.

First discovered on Tiritiri Matangi in 2001, they are capable of killing native insects, lizards and even birds, and compete with them for food resources. Once established, they are extremely difficult to remove.

An innovative bait and detection methods developed by DOC scientist Dr Chris Green were integral to the decade-long effort to clear the ants from Tiritiri Matangi.

For three years no Argentine ants have been found on the island, and DOC is now able to formally declare them eradicated.

“Achieving this goal is a tribute to the hard work and dogged determination of Dr Green and volunteers from the Supporters of Tiritiri Matangi,” Ms Barry says.

Lessons learned from the Tiritiri Matangi eradication have already been applied on islands overseas.

Biosecurity measures are in place to minimise the risk of reinvasion. Surveillance systems to detect any new ant incursions have also been established.

“The risk of reinvasion on Tiritiri Matangi – or other pest-free islands – is very real, and visitors need to make sure they comply with DOC’s biosecurity guidelines.”

For more information on Argentine ants and biosecurity measures to prevent their spread visit