Pest detection dog Vito inspecting
Image: DOC


An Argentine ant detection dog has averted a potential disaster on Matiu/Somes Island, after finding a large colony of the invasive pest species near building materials destined for the island’s new wharf.

Date:  21 March 2024

Vito and his handler, DOC Senior Ranger Adeline Bosman, were inspecting the mainland site and its surrounding area in case the highly aggressive ants were present as they are a serious risk to native species, which have no defence against them.

Adeline says this is a good news bad news situation.

“The bad news is the ants are present,” says Adeline, “and that they exist in New Zealand at all. The good news is we found this lot before they made it onto a pest-free island, and can handle accordingly.”

First detected in Auckland in the 1990s, Argentine ants are especially difficult to deal with due to their unusual behaviours compared to other ant species. They are highly aggressive, swarming over and biting perceived threats or obstacles, and possess multiple queens per colony. When they detect they are being poisoned, they cease foraging in that area and move away to continue the colony elsewhere.

“Certified conservation dogs are the only active tool we have, alongside passive tools like cameras and traps,” says Adeline. “If it wasn’t for dogs like Vito, we’d be at a much higher risk of these ants spreading even further afield.

“These dogs help prevent disasters before they happen.”

DOC will treat the site and its environs and eradicate the local population of ants before the materials are shipped to Matiu/Somes Island to construct the new wharf, intended to be in service by summer 2024.

Adeline and Vito continued their work in Wellington last week, inspecting sites on Matiu/Somes Island, Mana Island, and Kapiti Island. No incursions of Argentine ants were found on any of these pest-free islands.

“If you’re visiting pest-free islands, please comply with biosecurity regulations and check your clothes and packs,” says Adeline. “We don’t all have Vito’s nose!”

Vito is certified under DOC’s Conservation Dogs Programme. Air New Zealand is the national partner for the Programme, and their investment helps DOC run a world-class programme offering mentoring, training, and certification to dog handler-teams around New Zealand.


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