A South American invasion threatens to destroy one of Northland's vital ecological reserves.
The Department of Conservation is investigating the discovery last week of Argentine ants on a track leading to the Bream Head Scenic Reserve.
The ants were also found around houses at nearby Urquharts Bay.
Conservation officer Andrea Booth said the
discovery was a serious concern because the scenic reserve was of high ecological value.
The area is a sanctuary for many endangered plants and animals, including native snails, beetles and lizards.
It also contains what conservationists regard as the best piece of coastal bush in Northland.
Argentine ants are extremely aggressive, capable of eliminating other types of ant colonies, destroying and eating other insect species and earthworms, and competing with birds for food.
They have also been knownto climb trees and kill baby birds in the nest.
"If the ants get into the reserve they could devastate it. We're just hoping they haven't spread that far," Ms Booth said.
DoC will lay non-toxic traps in the Urquharts Bay area next week to determine the extent of the infestation. Once that is completed, the department will decide what action to take.
"We want to control them before they reach the bush where there will be a lot more food resources."
Ms Booth said DoC needed to act quickly because the bait that killed the ants was effective until mid-March, after which the ants went into a hibernation-type state and would not eat it.
She said the ants were often unwittingly spread by humans through items such as potplants and timber.
Argentine ants were first discovered in New Zealand in 1990 and have spread to Northland, Waikato, Bay of Plenty, Wellington, Nelson and Christchurch.
- NZPA
nzherald.co.nz/environment
