The Ministry for Primary Industries (MPI) has found 2 more larvae of the Culex sitiens mosquito in the Kawau Parua Inlet, north of Helensville.
Extensive sampling and trapping in a 5-kilometre area around the initial find site found no other signs of the exotic mosquito. However, after returning to the initial find site on Friday, 2 more larvae were found.
MPI's incident controller Dr Catherine Duthie says the new find is not definite evidence that there is an established breeding population of the mosquito, but does make it more likely.
"We will conduct further intensive sampling in this area over the weekend in order to identify if there is a breeding population, and if so, how far it has spread," Dr Duthie says.
"If there is a breeding population, it is likely that MPI will undertake a programme to eradicate the mosquito from New Zealand. MPI has successfully eradicated exotic mosquitoes in the past."
Dr Duthie says MPI officials will have the necessary permissions to begin spot treatment when suspicious larvae are found as part of the sampling and trapping process.
"As sampling and testing are being conducted our field staff will treat any suspicious larvae with a product called Vectobac, which is an inert bacteria granule.
"There are no human health concerns from using this treatment."
MPI is also investigating how the mosquito may have entered the country.
Background on Culex sitiens
Culex sitiens is wide-spread in Southeast Asia, the South Pacific and Australia. It is known to transmit diseases such as Ross River virus. However, this is not currently a risk for New Zealand as this disease is not present here. Culex sitiens may also be able to transmit Japanese encephalitis, but this has not been observed outside of a laboratory setting.
Who to contact
- If you see unusual mosquitoes, call the toll-free Mosquito Hotline number 0800 MOZZIE (0800 66 99 43).
- If you have health concerns after having been bitten by a mosquito, phone the Ministry of Health's Healthline on 0800 61 11 16.