A fourth fruit fly has been found in Auckland, less than 300 metres from the last detection in Northcote.
The latest discovery has prompted further biosecurity restrictions on the movement of fruit and vegetables in the Northcote area.
The 200 metre restricted radius in Northcote will be extended towards the south east to include the latest finding.
"We are taking further measures to ensure we are doing everything we can sensibly do to find any other fruit flies in the area," Ministry for Primary Industries spokeswoman Catherine Duthie says.
The male fly was found in a surveillance trap just outside the A Zone controlled area, but within Zone B, yesterday - around 270 metres away from the last detection in Northcote.
Duthie said while it was disappointing to find another fly, it did show the effectiveness of the surveillance programme.
"Importantly, we still have no evidence of an established breeding population."
All 5243 fruit fly traps in the greater Auckland area have now been checked. That includes 629 traps combined in the three controlled areas, which are being checked every day or every third day depending on the area they are in.
A detailed map of the controlled area and a full description of the new boundaries and movement controls is at biosecurity.govt.nz/fruit fly.
Duthie said due to the new find MPI are taking the precautionary approach of continuing the response in Devonport for another week rather than closing it at the weekend.
What to do if you find a fruit fly?
• Keep hold of it and call 0800 80 99 66.
• If you live around Devonport, Ōtara, or Northcote: find out if you're in the Controlled Area. If so, you will need to follow legal restrictions around movement of fruit and vegetables. Remember – if in doubt, don't take it out.
Timeline of Auckland's Queensland fruit fly discoveries:
February 14: Single male Queensland fruit fly located in Devonport, on the North Shore.
February 20: Another single male Queensland fruit fly found on the North Shore, this time in Northcote.
February 25: Another single Queensland fruit fly found in Northcote.
February 28: A third single male Queensland fruit fly detected in Northcote, 270 metres from where the last was found.