Biosecurity teams and fruit and vegetable growers are on alert after a Queensland fruit fly was found in Auckland.
The single male fly was caught in a "surveillance trap" in Devonport on February 14.
Queensland fruit flies can damage a wide range of fruit and vegetables and if they gain a foothold in New Zealand could also lead other countries to impose trade restrictions on the country's exports.
However, Biosecurity NZ spokeswoman Dr Catherine Duthie says the find does not mean New Zealand has a fruit fly outbreak.
"The Queensland fruit fly has been detected six times before in northern New Zealand – in Whangārei and in Auckland," she said.
"Of these detections, only one, in Auckland in 2015, turned out to be a part of a wider breeding population and this was successfully eradicated by Biosecurity NZ."
Authorities spent $13.6 million eradicating the last major fruit fly threat in 2015.
However, the Ministry for Primary Industries said at the time the money was well spent given the risk the flies pose to the country's horticulture exports, which are forecast to rise 12 per cent in 2019 to $6 billion.
The MPI has a network of about 7500 fruit fly traps across the country but Biosecurity teams had been busy in Auckland this week setting additional "lure traps to determine if other flies are present in the area".
"It is vital to find out if this insect is a solitary find or if there is a wider population in Auckland that will need to be destroyed," Duthie said.
Biosecurity NZ said it was working with international trading partners and partners in the horticultural industry to minimise the risk.
As a precautionary measure, restrictions will be soon be put in place on the movement of fruit and vegetables out of the area, it said.
Instructions to the public about these controls and the exact area affected will be issued shortly.
A brochure with information about the fruit fly and controls will go to homes in the area later today.
"In the meantime, we ask people who live in Devonport not to move any fruit or vegetables from their homes," Duthie said.
"You may notice increased activity in the neighbourhood as we go about inspections and trapping. Our inspectors will seek permission to investigate fruit trees on your property if required."
The most likely way that fruit flies can arrive in New Zealand is in fresh fruit and vegetables.
To reduce the risk there are regulations governing the commercial import of fresh fruit and vegetables, while air and sea passengers are not allowed to bring them into the country.
More information about the Queensland fruit fly can be found on the MPI biosecurity website.