The Queensland fruit fly threat should be obliterated within a few months but authorities are asking residents of affected areas to stay vigilant.
The Ministry for Primary Industries (MPI) said it was completing efforts to eradicate the pest.
Restrictions on moving fresh fruit and vegetables were placed in areas around Grey Lynn, Auckland, when the invasive fly was found in February.
A few properties with fruit fly infestations were treated with insecticide sprays and ground treatments.
"In addition to the treatments, MPI extended its existing network of surveillance traps to locate any flies that could remain in the area. No flies have been trapped since March 2015," the ministry added.
MPI planning manager Edwin Ainley said fruit flies were usually inactive over winter but a "telling time" was looming.
"Now that the weather's warming up, if any flies did manage to survive the earlier treatment blitz, they'd be on the wing and we'd trap them in our extensive network of lure traps."
Mr Ainley said in the past week MPI resumed more frequent checking of surveillance traps in the A Zone of the controlled area, closer to where the first flies were found.
"Residents in this central A Zone can expect to see officials checking the traps twice weekly now," he said.
The ministry said it was confident of beating the fruit fly eradication but the next few months were needed to ensure success."
We can't assure our trading partners that the population is gone until the empty traps confirm our success," Mr Ainley said.
"At this stage, we hope to declare eradication and end the movement controls on fruit and veges before Christmas."