"This is an isolated incident and shows the system working as it should.
"In the last two years around 125 new quarantine inspectors and more detector dog teams are working on the frontline, and we have new x-ray machines installed at our international airports."
Both Labour and the Green Party hit out at the Government, saying the discovery was proof that cuts to MPI had led to "flimsy" biosecurity controls at the nation's borders.
Horticulture New Zealand warned of the threat to $5 billion horticulture industry and called for the reinstatement of mandatory x-ray screening of all inbound luggage at international airports.
Restrictions in place
A 1.5km circular exclusion zone has been set up by MPI, restricting the movement of fruit and some vegetables in Grey Lynn and taking in parts of Western Springs, Mt Albert, Ponsonby and Kingsland.
Eden Park and Auckland Zoo both lie inside the zone.
The restrictions are likely to be in place for at least two weeks, MPI said. Last year's fruit fly find in Whangarei saw restrictions in place for 20 days, and cost the country almost $1 million.
"These legal controls are an important precaution while we investigate whether there are any further fruit flies present," MPI chief operations officer Andrew Coleman said.
"Should there be any more flies out there, this will help prevent their spread out of the area."
He urged people to abide by the rules, saying previous operations had shown public support "is vital to success".
"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," he said.
How it'll affect residents
Two Countdown supermarkets sit within the exclusion zone -- on Williamson Ave and Richmond Rd -- as well as a number of other local fruit and vegetable shops.
"It's an inconvenience for our customers but we absolutely recognise that Queensland fruit fly is a serious biosecurity risk and we're happy to help," a Countdown spokeswoman said.
"Customers who live in the quarantine area can still buy fruit and veges from our stores to eat inside the area, but they can't take it from our stores or their homes to anywhere outside the controlled area."
Auckland Zoo said the restrictions would not have any impact on bringing food in for the animals, but it was working with MPI on the disposal of waste fruit products.
A spokesman for the Cricket World Cup said MPI would supply specialist bins for fans to dispose of fruit and vegetables after the match between New Zealand and Australia on February 28.
The weekly Grey Lynn Farmers Market also falls within the cordon, but manager Louise Carr-Neil said it would still go ahead this Sunday.
"A lot of our growers are in Kumeu, they're able to bring fruit and veg into the market with no problem, but people who buy fruit and veg at the market, excluding leafy greens and root vegetables, won't be able to take it outside of that 1.5km radius," she said.
"Of course that's going to affect the market this week, and we're hoping it will be cleared up as soon as possible.
"But a lot of our customers are based very close to the market, and that exclusion zone is actually pretty big, so the market is going ahead as normal."
Grey Lynn Residents Association committee member Nicola Legat said she was concerned about the "economic impact on our local businesses", and said everyone was "anxious" about how long the restrictions would be in place for.
But she added: "I'm sure that Grey Lynn people will do their utmost to participate in whatever it is that we need to do."
Horticulture New Zealand president Julian Raine laid the blame for the fruit fly breach on "Australia's inability to control the pest" and urged the reinstatement of mandatory luggage x-rays at airports.
"It is not acceptable to go through this drama every summer. New Zealand horticulture deserves better protection."
Labour: It's a 'failure', PM says no it's not
Labour's spokesman for primary industries, Damien O'Connor, said the fruit fly discovery showed there was a "failure" at New Zealand's borders, and blamed Government cuts for leaving MPI short of experienced staff.
Green Party biosecurity spokesman Steffan Browning said the discovery showed New Zealand's biosecurity measures were "flimsy".
"We also have to question whether cuts to frontline biosecurity staff since 2012, when the fruit fly incursions began, have had an effect on the quality of screening."
Prime Minister John Key hit back at Labour's allegations on TV3's Firstline this morning.
"There's been all sorts of changes within the Ministry for Primary Industries, but biosecurity's a top priority and in fact actually the emphasis has changed very much on making sure that we do what we can to stop pests like the Queensland fruit fly.
"But at the end of the day, these things are prolific in Australia, a lot of fruit comes across the Tasman [in] a lot of different ways and so the big job now is to make sure that within that Grey Lynn area that we're very vigilant.
"We're a very open country and a lot of fruit comes across and a lot of people come across."
The ministry had been changing the way it carried out its biosecurity work, which had been very successful, Mr Key said.
Fly probably arrived in piece of fruit
MPI chief operations officer Andrew Coleman said the fruit fly probably came to New Zealand in a piece of fruit in an egg or larvae state.
"That's the normal way that they would come in because these insects have to pupate, that means they have to burrow into the ground.
"Having burrowed into the ground, two or three weeks later, it will come out as a live insect and thankfully, because of the surveillance trapping system that we've got, this insect went straight to one of the traps."
Australia had a burgeoning fruit fly population in Queensland, New South Wales, parts of Victoria and some parts of South Australia, Mr Coleman said.
"We know that it's prevalent there. We've been working with the Australians about what we should do, and can do and require them to do around those importations that we make of Australian fresh fruit and produce."
Every year 22,000 tonnes of fresh produce from Australia was imported to New Zealand, Mr Coleman said.
"People may ask why we're putting so much effort into an individual insect - well, the reality is for New Zealand, we don't want a breeding population.
"In Australia they have breeding populations, so what happens is they have to declare that internationally and because of that declaration, there's a whole lot of restrictions that can now be placed and have been placed on Australia exporting fresh fresh fruit and produce - we don't have those same restrictions."
MPI had 7500 surveillance traps which were checked every two weeks usually, but the traps were now being checked every three days as the ministry was in a "response mode", Mr Coleman said.
Little bug - big problem
The discovery of a Queensland fruit fly in Auckland has raised concerns about the effect on New Zealand's horticulture industry. Here's what you need to know.
What is the Queensland fruit fly?
The 5-8mm fly is considered to be Australia's most serious insect fruit and vegetable crop pest. Females lay eggs inside ripening fruit, which their offspring feed on, making the fruit inedible and unsuitable for sale.
Why is the Auckland find so bad?
New Zealand's horticulture industry is worth $5 billion a year, and MPI says the fruit fly has the potential to "seriously harm" crops.
Have we had this issue before?
It is the sixth time a Queensland fruit fly has been found in New Zealand - in Whangarei in 1995, 2013 and 2014, and in Auckland in 1996 and 2012.
What are the consequences for trade?
Many countries might ban produce imports from New Zealand if there was an established fruit fly population here.
