Biosecurity workers are busy dissecting fruit as the hunt continues in Auckland for more Queensland fruit flies.
The Ministry for Primary Industries said no more of the pest had been detected since the discovery of a single male fly in central Auckland this week.
The exclusion zone around the Auckland suburb of Grey Lynn was in place, with almost 200 pheromone traps designed to trap male flies.
The zone included Eden Park, Auckland Zoo and two Countdown supermarkets and was expected to be in place for another two weeks.
No produce within the zone was allowed to leave.
MPI Chief Operations Officer Andrew Coleman said to discover whether there were female flies around, up to 600 kilograms of fruit would be carefully dissected to look for eggs or larvae.
"It's fruit that definitely has come from both zone A and it's either taken from trees or out of gardens in those zones or indeed out of the bins that people will putting their waste fruit and vegetables in.
"The reason we do the dissection of fruit, which we will do over the next two weeks and about 600 kg of fruit and vegetable will be dissected through the laboratory system that we've set up in Auckland, the reason we do that is the best evidence of female insect is the laying of the eggs or indeed larvae, so it's cut into 3mm slices and then each slice is microscopically examined."
Mr Coleman said the cost of an incursion was up to $1.5 million each time.
And that was a concern for Horticulture New Zealand chief executive Peter Silcock.
"The proposal is in the future that this will be shared between Government and industry, and industry is very nervous about that if we don't have a good system in place to stop these things occurring in the first place and we certainly don't want to go on like this where every summer we're dealing with a number of detections in the traps.
"That's not a sustainable position for us and it creates a huge risk for the industry," he said.