Food and vegetable restrictions on Auckland's North Shore, imposed after the detection of a Queensland fruit fly, could go on months if MPI finds the insect has bred.
Sixty biosecurity staff are currently in Devonport speaking to residents and businesses within the controlled area following the discovery of a single male Queensland fruit fly in a surveillance trap last week.
The controlled area has blanketed Devonport, reaching as far north as the fringe of Narrow Neck and west to Stanley Point.
The "hot zone", measuring 200m x 200m, covered several streets in the town centre.
This morning MPI confirmed no further fruit flies had been found since the first discovery on Thursday.
The ministry warned that if it established here, the Queensland fruit fly could seriously harm fruit and vegetable crops and affect exports of some produce.
"To date, no further signs of fruit flies have been found," it said.
However, if a breeding population was detected, MPI said, the operation would go on for months.
"If no further flies are found, the restrictions will be lifted by March 1."
With just the one fruit fly detected, there were no plans to change the restrictions.
Response staff were working with local retailers to explain the detail of the movement controls and how they may impact their businesses.
Biosecurity New Zealand's bio-secure mobile field laboratory had also been established at the Devonport Naval Base.
Local retailers were eligible to apply for compensation for verifiable losses incurred as a result of the legal directions.
Current work involved extending the network of traps; inspecting home gardens in the area for plants that could provide suitable habitat for fruit flies; taking fruit and vegetable samples for testing and providing information to local residents and visitors.
On top of the 60 staff in Devonport, which was likely to grow, another 20 were working from the national headquarters in Wellington.
This morning MPI was yet to visit all 200 houses within the hot zone.
North Shore MP Maggie Barry, who was Conservation Minister during the 2015 fruit fly incursion in Grey Lynn, said there was a lack of information from authorities.
She said the biosecurity response needed "to be fast, it needs to be very tidy and there needs to be a lot of information".
She said she was having trouble getting up-to-date information and was disappointed that the minister took four days to visit the area.
"They have not kept us in the loop. It is very difficult for us to help spread the information on what needs to be a very comprehensive public consultation.
"As the local MP, I fielded many, many questions from anxious members of my Devonport community in particular about what they should do. "
"We need better information."
Politics should not come into play, she said.
"Parents and school children and retailers are none the wiser on day five of what they ought to be doing."
During the last major fruit fly threat in 2015, authorities spent $13.6 million eradicating 14 flies.
However, MPI 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.
Takapuna and Devonport Local Board deputy chair Grant Gillon lives in the hot zone and said he was impressed with the biosecurity response so far.
"The closest school are slightly outside the A zone, there are a couple that sit in the B zone."
He had spoken to several businesses in the area who had said to him they were concerned about visitor numbers around the village.
"There is probably a little bit of uncertainty around it.
"But everyone seems to be taking it in their stride," he said.
A fruit and vegetable store had raised concerns on how fruit and vegetable purchased by people living outside the control zone could take their goods home.
"I haven't noticed any drop off yet."
Biosecurity New Zealand has imposed a ban on taking fresh fruit and vegetables outside an area around Devonport, including Cheltenham and part of Stanley Point.
Devonport locals we urged to contact the response team on 0800 80 99 66 if they spotted the insect.
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 response can be found here