The Ministry for Primary Industries is scaling back its operation for the Queensland fruit fly pest found in the Auckland suburb of Grey Lynn.
It is reducing the size of the control area, checking bait traps less often, and making fewer backyard visits.
The Ministry said it was so certain of the location of the infestation it could now reduce the size of the risk zone, although restrictions on the movement of fruit and vegetables would remain.
No fruit flies had been found for two months.
The Ministry said the insects were not active in cooler weather, so staff won't know for sure until spring when any flies still present would become active again.
Fourteen Queensland fruit flies were found in February, and a 1.5 kilometre quarantine area around the first find had been put in place.