Southern saltmarsh mosquito larvae have been found on the Whangaparaoa Peninsula north of Auckland, prompting the Ministry of Health to extend its eradication programme.
The larvae were found near Shakespear Regional Park on Tuesday during routine checks. Yesterday, the Associate Minister of Biosecurity, Marian Hobbs, authorised treatment to prevent the mosquitospreading.
The saltmarsh mosquito can carry the Ross River virus. People who contract the disease suffer symptoms similar to flu which may last for months or even years. Treatment is available to relieve the symptoms.
So far all cases reported in New Zealand have been contracted overseas.
The Ministry of Health's chief technical officer (health), Sally Gilbert, said three sites in an area of about 22ha had been treated with s-methoprene, which stops mosquito pupae hatching into adults.
She said the product, which was coated on sand granules, had been used successfully as part of an eradication programme in Hawkes Bay, Tairawhiti and Kaipara.
It had no long-term residual effects and studies of its use had shown no harmful impact on other animals or insects. Efforts had been made to contact affected landowners before treatment began.
Auckland Public Health staff and New Zealand Biosecure contractors were surveying all possible habitats, using aerial photographs, maps and helicopter surveillance.
The National Party's biosecurity spokesman, Shane Ardern, said the find mocked the Government's biosecurity initiatives.
"Last November Labour claimed it had successfully eliminated the southern saltmarsh mosquito from Kaipara and Gisborne/Napier regions," Mr Ardern said.
"But the latest discovery shows that the $37 million Labour spent on eradication was wasted, as its border controls are failing to stop further incursions.
"How many more millions will we spend on eradication and surveillance when better border control and more money spent at the battlefront would eliminate the necessity for clean-up programmes."
He said the Government was placing people at risk with its sloppy attitude toward biosecurity protection.
Ms Hobbs said Mr Ardern was incorrect in saying the Government had claimed in November that it had eliminated the mosquito from Kaipara.
The mosquito had been eradicated from Mahia and Napier but the battle was continuing elsewhere in Hawkes Bay, Gisborne and Kaipara, she said.
Water babies
* The southern saltmarsh mosquito lays its eggs on vegetation just above the waterline but wetting is vital for the eggs to hatch.
* High tides, heavy rain and wind which increases the size of waves can all encourage hatching.
