The mosquito caught in a trap at Port Auckland's Shed 8 last Thursday has been confirmed as an asian tiger mosquito.
The initial biosecurity response mounted by the Ministry of Health was yesterday handed over to Ministry of Agriculture and Fisheries' Biosecurity NZ arm.
The biosecurity staff arenow trying to work out if the mosquito was a new arrival or from a population which has already secretly established in Auckland.
"We can't say at this stage if we're dealing with a resident population of these mosquitoes or if it was imported," Biosecurity NZ spokeswoman Sonya Bissmire said.
She said the male mosquito was an unexpected catch in the light trap, but though only one mosquito had so far been found, the incursion had to be taken seriously because the species was capable of spreading many serious human diseases, including dengue fever, yellow fever, and various types of encephalitis.
An estimate of the cost in 2001 based on the spread of the less-fatal disease ross river fever - also spread by the asian tiger mosquito - was conservatively put at more than $38 million in the Auckland area alone.
Much of the cost would come from the effects on the workforce of large numbers of people suffering chronic fatigue, with initial estimated case rates of 10,000 people per 100,000 population.
Not only would the economy be at risk - so would the outdoor lifestyle around Auckland: the mosquito is an aggressive outdoor day biter - in one survey of biting rates a level of 30 to 48 bites per hour was recorded.
She said the public could help by reporting unusual mosquito activity - such as aggressive daytime biting.
Adults, about 5mm long, have conspicuous patterns of very black bodies with white stripes, and a distinctive single white stripe down the length of the back.
Sightings can be reported to 0800 MOZZIE (0800 669943).
