Fourth fruit fly found in Grey Lynn

A Queensland Fruit Fly.

The Minister for Primary Industries has confirmed a fourth fruit fly has been discovered in Auckland.

The single male fly was caught in a trap late last night.

Residents of Grey Lynn in central Auckland will have to get used to restrictions on transporting fresh produce.

The exclusion zone could be expanded and remain in place for up to three months.

MPI will confirm further details about their plans this morning.

Primary Industries Minister Nathan Guy says such a find is to be expected.

He says the response is good, with officials cracking into gear with baiting, spraying and turf management.

Nathan Guy says given the number of flies detected, the response could take a couple of months to run its course.

But Waitemata Local Board deputy chair Pippa Coom says locals are already adapting to the new rules.

"I think everybody wants to really do the right thing, because the implications could be devastating for our agriculture."

One financial expert is expecting the economy to wake up to the potential threat of the Queensland fruit fly over the next few days.

Andrew Kelleher from ASB Securities says he's surprised by the response from exporters so far.

"The reaction has been fairly muted up until now and I do wonder if this has been a little bit downplayed."

Andrew Kelleher says the scare poses potentially significant export implications, putting a billion dollar industry at risk.