Infestation of ants hits housing areas

Two blocks of homes in Stoke, Nelson, have been infested by argentine ants and it is unlikely Nelson will ever be fully free of them, a scientist says.

Nelson City Council is planning a controlled poisoning programme and is warning residents not to try to deal with the ants themselves as they will go into a "breeding frenzy".

Homes on The Ridgeway and Arapiki Rd are believed to be affected.

Landcare Research entomologist Richard Toft said the omnivorous ants, considered a major pest because of their ability to form supercolonies and their resistance to usual ant poisons, had been reported in the area.

"At this stage nobody's gone out and mapped it totally but it covers a couple of blocks."

An eradication programme was carried out when the ants were found at Port Nelson in 2001 and 2003, but this was the first time the ants had been found in a residential area, he said.

"In the port operations it got down to just a very few last remaining colonies which are very difficult to locate and get rid of.

"We're attempting to mop those up this summer."

Territorial authorities did not have room in their budgets for a concerted focus on eradicating the ants, which meant there was a "gap in New Zealand biosecurity in terms of urban areas", Mr Toft said.

Planning and consent divisional manager Rod Witte said the council planned to contract Nelson Pest Control Services to find out how large the infestation was and to co-ordinate a bait poisoning programme.

Mr Witte said landowners would be asked to pay for the bait, at $40 a tube, and the council would pay for Nelson Pest Control's services.

One tube would be enough to treat an average residential property.

- NZPA