Traps set up in Whangarei to lure any Queensland fruit fly have so far found no more of the insect pests.
A male fly was found in a surveillance trap in the suburb of Parihaka on 1 April, about 400 metres from where one was found in January this year.
Ministry of Primary Industries staff have set up traps to determine whether any more fruit fly are in the area.
In an update released on Sunday, the ministry said the first clearance of traps in Zone A was completed on Saturday and no fruit fly were found.
Traps in Zone A are cleared daily and traps in Zone B are examined every three days. Zone A extends 200 metres from the site of the detection and Zone B goes from that boundary out to 1500 metres.
None of the insect pests have been found on fruit collected from properties near where the male fly was discovered. A number of insects brought in by the public were found not to be fruit fly.
The ministry said restrictions on the sale of fruit and vegetables still apply in some areas as an important precaution while it continues its investigation.
It said an extensive trapping network has been set up and and gardens and rubbish bins in the affected area are being inspected for any signs of the insect pest.