Summer revellers in Kaipara, Coromandel and Wairau, near Blenheim, are being urged to be alert to aggressive virus-carrying mosquitoes.
The Ministry of Agriculture and Forestry Biosecurity has been eradicating the Australian southern salt marsh mosquito, which can be a carrier of the Ross River virus, in those areas.
Ross River virus causes symptoms such as sore muscles and joints, fever, chills, sweating, headaches and tiredness. Though it is not fatal, in some cases it can take more than a year to recover from.
Incursion manager David Yard said the risk of southern salt marsh mosquito activity was low, but people needed to remain vigilant and immediately report any possible findings.
"Unlike most native species, the southern salt marsh mosquito is a vicious daytime biter.
"We want people to keep watch when they're out enjoying the sun near salt marsh areas - as this is the time these mosquitoes would be active."
Anyone bitten by a mosquito near a salt marsh during the day should call the MAF exotic pest and disease emergency hotline on 0800 809 966. Land occupiers in the eradication areas should also notify the ministry if they planned to irrigate or were aware of any leaks, because rising water levels might cause dormant mosquito eggs to hatch, Mr Yard said.
The eradication, involving helicopter and ground treatments, was on track to be complete in 2009 providing there were no new finds, he said.
