A second Queensland fruit fly has been found in Auckland - this time on the North Shore.

The single male fly was found in a trap yesterday and is the second Queensland fruit fly to be found in the past week.

The first was discovered in a surveillance trap in Devonport last Wednesday.

The latest find - in the suburb of Northcote - means that an area of Northcote has now been placed under a Controlled Area Notice.

It is effective from today and restricts the movement of certain vegetables and fruits out of the controlled area; in a bid to prevent the spread of other fruit flies that may exist.

Ministry of Primary Industries director general Ray Smith said despite the discoveries, it did not signal an outbreak.

"We are totally focused on finding out if there is an incursion of the Queensland fruit fly in these areas.

"At the moment, there are two single males found quite some distance apart and there's no evidence of a breeding population.''

The MPI has field crew working in Devonport and now in Northcote. No further fruit flies have been found in Devonport.

An independent assurance review of New Zealand's air and cruise passenger pathways has also been commissioned and will start next week.

Australian expert Rob Delane - a former department secretary of the Department of Agriculture and Fisheries Australia - has been chosen to carry out the review.

Biosecurity surveillance coordinator Kerry King working in Devonport, Auckland, after a Queensland fruit fly was found last week. Photo / Michael Craig

Minister for Biosecurity, Damien O'Connor, said monitoring of the greater Auckland region would be stepped up after the second discovery.

"I have asked Biosecurity New Zealand to check the hundreds of traps within the North Shore area of Auckland by the weekend instead of the internationally accepted practice of once a fortnight - then to expedite a check of all 2000 Queensland fruit fly traps across Auckland.''

He said authorities needed to know what they were dealing with, to ensure the Queensland fruit fly does not establish here.

"We have an absolute commitment to tracking down and keeping New Zealand free of the harmful fruit fly, as we've done several times before - including in 2015, when $16 million was spent to get rid of a breeding population of 14 flies and larvae.''