Two more of the male Queensland fruit fly have been found in the Auckland suburb of Northcote, bringing the total to six.
Biosecurity New Zealand (BNZ) says the discovery means it is "zeroing in" on the flies and will increase its operational response.
The latest finds will mean an expansion of Zone A in Northcote and restrictions on the movement of fruit, vegetables and green waste, head of Biosecurity New Zealand Roger Smith said.
Zone A now extended south to the bottom of the Northcote Pt.
Detailed maps and information from the Ministry for Primary Industries can be found here.
"These recent finds mean we are zeroing in on the Northcote flies and we can increase our operational response.
"Our teams on the ground will be removing fallen fruit from backyards, inspecting compost bins and placing bait on fruit trees to attract and kill adult flies, in particular females.
"The baits are toxic to fruit flies. We have taken every precaution to make sure the baits are safe around people and animals. They are not harmful to bees.
"We will give people living in the area at least 24 hours' notice that we will place bait in their property and will provide them with detailed information about our programme."
There had been no further findings of the fly in Devonport since its first and only discovery on February 14.
However, because of the proximity to Northcote Biosecurity NZ would continue with movement controls and trapping.
"We will reconsider next Friday whether this needs to continue further.
"There is no need to undertake bait laying in Devonport."
No further Facialis fruit fly had been found in Otara.
Biosecurity NZ would review movement controls there at the end of next week.