By ANNE BESTON
The Ministry of Health says efforts to wipe out a southern saltmarsh mosquito infestation in East Auckland appear to have been successful.
The site where two larvae discoveries were made last week was kept under surveillance for five days but no more were found and no adults
were trapped, ministry spokesman Graeme Gillespie said.
Mr Gillespie said he did not rule out finding adult mosquitoes in the area, but ministry staff were "reasonably optimistic" the infestation at Taring Creek was a "rogue" event.
Of the 17 sites surveyed at Whitford, three had larvae identified as being southern saltmarsh mosquitoes.
The sites were in a one-hectare area and had all been treated with s-methoprene, an insect growth regulator that stops mosquito pupae hatching. The infestation was found during routine sampling.
Southern saltmarsh mosquitoes carry the Ross River virus. People infected can develop a wide range of symptoms including chills, headaches, aching limbs and tiredness.
Long-term health effects can include severe depression. All cases of Ross River virus reported in NZ have been contracted overseas.
After last week's discovery a Health Ministry team began surveying sampling sites along 25km of the eastern coastline, from Whitford to Miranda and Waiheke Island.
Mr Gillespie said traps to attract the mosquitoes had been set up at Whitford and would be closely monitored during the next few weeks.
The ministry is also fighting the mosquito in five other places.
Using aerial spraying of Bti, a biological larvacide, it is spending $5 million to eradicate the insect in Gisborne, Napier, Mahia and Porangahau and is trying to bring it under control in the Kaipara Harbour area with a view to eventual eradication.
The Kaipara area has the biggest infestation of the aggressive pest, with a potential habitat of more than 2000ha.
nzherald.co.nz/environment
