The Ministry for Primary Industries is investigating the find of a single Tau fly caught in a surveillance trap in the Auckland suburb of Manurewa.

The adult male fly was collected from a trap on Thursday afternoon and was formally identified later that day.

A single Tau fly has been discovered in the Auckland suburb of Manurewa earlier this week. The Ministry of Primary Industries is now investigating how the fly entered New Zealand. Photo: MPI

The Tau fly is not a direct threat to the kiwifruit industry but Horticulture New Zealand is closely monitoring the situation, says newly appointed chief executive Mike Chapman.

Mike, formerly of Tauranga, says the insect is not interested in kiwifruit and is not considered to be as economically threatening to the country's horticulture industry as the Queensland Fruit Fly.

But despite this, he says any detection like this makes New Zealand's fruit and vegetable exporters nervous and all efforts must now be focused on establishing the extent of any population, containing it and then eradicating it.

'We are confident this localised detection will be swiftly and effectively eradicated,” says Mike.

'And once again we find ourselves calling on the general public in Auckland to assist with a fruit fly detection, but we know everyone helps where they can and we greatly appreciate it.”

MPI Surveillance and Incursion Investigation manager Brendan Gould says only one fly has been found and it didn't mean there was an outbreak in New Zealand.

'We have a significant number of traps in this area which were all checked yesterday. No other flies were found,” explains Brendan.

'This fly is a species normally found in South East and Southern Asia and is used to a more tropical climate. It's very unlikely to be able to establish in New Zealand.”

The MPI has responded swiftly and teams are now in the field setting additional traps to determine if other flies are in the area.

If more are found they will take further actions to prevent the flies' spread.

'Unlike the Queensland fruit fly this insect has a much more limited range of host material and has a preference for cucumbers, pumpkins and zucchini. Though capsicum, beans, passionfruit and melons are minor hosts.

'We're not treating this lightly. While the Tau fly is a threat, it's not as widely damaging as the Queensland Fruit Fly.”

MPI has placed controls on the movement of certain fruit and vegetables in a defined circular area extending 1.5km from where the fly was trapped in Manurewa.

Pumpkin, melon, cucumber, capsicum, zucchini, beans and passionfruit plants and fruit cannot be moved outside of the Controlled Area.

Detailed maps of the controlled area and a full description of the boundaries, and full information about the rules are on the MPI's website.

Brendan says it is likely the restrictions will be in place for at least two weeks.

HOW DID THE TAU FLY ARRIVE IN NEW ZEALAND?

The MPI says the most likely way these flies can arrive in New Zealand is in fresh fruit and vegetables.

The ministry has strict requirements on the importation of fruit and vegetables to minimise this risk. Air and sea passengers are prohibited from bringing fresh fruit and vegetables into the country.

MPI has to date been highly successful in keeping this particular insect threat out of New Zealand crops.

'This latest find demonstrates the benefit and effectiveness of MPI's lure-based surveillance trapping network as an important part of our biosecurity system," says Brendan.

"The network involves some 7,600 traps set nationwide and checked on a regular basis. By setting traps for these pests, we're able to detect their presence early, have assurance about exactly where the problem is located and respond faster and more effectively where finds are made."

If you have seen the Tau fly call the the Ministry for Primary industries on 0800 80 99 66. For more information visit: www.mpi.govt.nz/tau-fly