One hundred kilograms of fruit have been dissected and a similar number of insect traps checked in Whangarei over the weekend and there's still no sign of another Queensland fruit fly.
A week ago a male Queensland fruit fly was found in an insect trap in Parihaka in Whangarei, the second such fly to be found in the area this year.
Ministry for Primary Industries deputy director general of compliance and response, Andrew Coleman, told Radio New Zealand the official hunt has a long way to go.
"A successful weekend, but it's only (been) two or three days with another 10 or 11 to go," Mr Coleman says.
He says the costs of the latest incursion are mounting.
"We incur costs on a day to day basis but we normally tally them up at the end when invoices come in. Because we're not just deploying our own resources we're deploying other organisations' resources as well and obviously they have to be paid for."
The ministry says members of the public in Parihaka have captured and handed in four suspect insects, but none of them were fruit flies.