Mr Gould said MPI had responded swiftly.
"We have teams in the field now setting additional traps to determine if other flies are in the area, and they will take actions to prevent spread out of the area if more flies are found.
"It is vital to find out if this fly is a solitary find or if there is a wider population in Auckland."
Unlike the Queensland fruit fly, which when found in Auckland last year sparked a widespread containment operation, the Tau fly had a much more limited range of host material, with a preference for cucumbers, pumpkins and zucchini.
Capsicums, beans, passionfruit and melons were "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," Mr Gould said.
Pumpkin, melon, cucumber, capsicum, zucchini, beans and passionfruit plants and fruit are now not allowed to be moved outside of the controlled area.
"Based on our experiences with Queensland fruit fly last year, our operations have shown that public support is vital to success and we have always had terrific community buy-in," Mr Gould said.
"We appreciate this will be inconvenient for the many people living in and around the controlled area, but compliance with these restrictions is a critical precaution to protect our horticultural industries and home gardens."
The restrictions would likely be in place for at least two weeks.
Horticulture New Zealand said it was closely monitoring the response to the fly.
Chief executive Mike Chapman said despite the fly not being considered as serious a threat to New Zealand's economy as the Queensland fruit fly, it still made the country's fruit and vegetable exporters nervous.
All efforts must now be focused on establishing the extent of any Tau fly population, containing it and then eradicating it.
"We are confident this localised detection will be swiftly and effectively eradicated," Mr Chapman said. "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."