New Zealand's horticultural industry is on high alert after the discovery of a Queensland fruit fly in a surveillance trap in Auckland.

The Ministry for Primary Industries said it responded swiftly by setting up additional traps to see if other flies are present in and around the inner Auckland suburb of Grey Lynn.

It has also established an exclusion zone restricting the movement of fruit and vegetables from the area.

Chief operations officer Andrew Coleman told Pacific Beat trade with Australia could also be affected if more flies are found and the situation will continue to be monitored closely.

"We know that the Queensland fruit fly population is in Queensland and New South Wales, and in some parts of South Australia and Victoria, we know that they are prevalent in those areas, and we are monitoring all trade, and we have been for some time," Mr Coleman said.

Horticultural experts warned the fruit fly's presence could have serious consequences for New Zealand's horticultural industry, with the possibility of damage to a wide range of crops if more of the flies are in the country.

"It's initiated significant response," Mr Coleman said.

"We will be looking to prove hopefully that we don't have a breeding population in New Zealand.

"Pleasingly in the past that's been the case in previous single insect finds."

Mr Coleman said he was still unsure how the male fruit fly got to New Zealand.

"There's many ways of getting from Australia or other places where we know they have populations of fruit flies, specifically the Queensland fruit fly which this one is," he said.

"It could be commercial cargo or a shipping pathway... or it could be a small craft pathway, it might be a freight cargo or a freight parcel pathway as well as it may be a passenger who's come through the airport with undeclared fruit in their bag."

The Queensland fruit fly is a native of Australia, and is one of the most damaging pests for fruit and vegetable crops.

It lays its eggs in ripe fruit, from which maggots then hatch and tunnel through the flesh of the fruit turning it into pulp, destroying the fruit and leaving it inedible.

Fruit flies spread via produce infested with their larvae or maggots, which then mature into adult flies.

The fruit fly has been detected five times before in New Zealand - in Whangarei in 1995, 2013 and 2014, and in Auckland in 1996 and 2012.