Argentine Ants – A Threat to Kapiti Island

Earlier this year, concern was expressed over the outbreak of Argentine ants in Kapiti. Argentine ants are one of the most invasive ant species in the world. The species first settled in Auckland in 1990 and have been spreading across New Zealand ever since. They are a highly competitive species who will compete with kiwi and other native birds to get food such as lizards and insects.

When the ants broke out in Kapiti, a number of reports were made, stating that they had infested cars, homes and even one person’s dishwasher. A group of residents in Raumati had begun creating a plan to get on top of the problem. 

Now, the issue has re-emerged following the ants being found at Paraparaumu Beach, near the departure point to Kapiti Island. Soon after the discovery, DOC made a call for a robust quarantine regime. If the ants were to reach Kapiti Island, they would pose a huge threat to the native bird sanctuary. DOC was given permission from KCDC and the Kapiti Boating Club to poison the nest found near the Kapiti Island departure point, an area on council land.

Jake Mace from DOC has said that they will continue to monitor the area for signs of reinvasion and do ongoing control if needed.

The ants form large nests which can turn into supercolonies and become interconnected. Because of this, being able to spot the ants is critical, so that residents can get on top of them before they become a problem. It is important to recognise that getting rid of the ants is a job for experts and home remedies are unlikely to help you if you have an infestation.

The ants are about 2-3 mm long, are honey coloured and tend to travel in large trails (often 5 or more ants across). The ants also tend to travel over objects rather than around them and have been known to run up and down people’s legs.

Kapiti Mayor K Gurunathan has commented on the matter, stating that the infestation threatening the reserve was a  “clarion call for a proper best practice biosecurity facility at Paraparaumu Beach for visitors headed to the highly valued nature reserve”, and that the infestation highlighted the continuing “lack of such a basic protective shield needed for Kapiti Island’s high biodiversity values”

Letting even one of the ants reach Kapiti Island could be a potential biosecurity disaster according to Jake Mace, and those travelling to Kapiti Island have been urged to check their gear very very carefully. A response plan on the island is also being set into place so that the ants will be picked up quickly if they do reach the island.

“We can eradicate them if they get there – that’s totally feasible. However, robust quarantine measures to minimise the risk of them getting there is our first line of defence”