Spring is in the air and the Ministry for Primary Industries says it is on high alert for any amorous Queensland fruit flies that have survived the winter.
Fourteen of the pest flies have been found in Auckland since early this year, but the last one was caught in March.
An established population of the flies could be devastating to New Zealand's multi-million dollar horticulture industry.
The ministry's fruit fly planning manager Edwin Ainley said any fruit flies still in Auckland would have been over winter and not likely to have been breeding.
Biosecurity staff had still been checking the 360 traps set in the fruit fly zone - a 1.5km radius from the Grey Lynn house where the first fly was found in February - but had not found anything, Mr Ainley said.
"We are obviously heading out of winter into the spring/summer period... so if they have survived our extensive treatment programme to date, this is when we expect to find them in the traps over the next few months."
Mr Ainley said he was confident the eradication programme had worked.
"We're going to verify this by not catching any further flies throughout the spring [and] summer months, and also gaining agreement from our international trading partners," Mr Ainley said.
The ministry hoped to do that by Christmas, he said.