The discovery of a Queensland fruit fly in Auckland has come at the worst possible time for fruit and vegetable exports, the horticulture industry says.
The Ministry for Primary Industries has notified New Zealand's trading partners that a male Queensland fruit fly has been found in a surveillance trap in Avondale on Tuesday.
Biosecurity staff are working to find out whether a breeding population has been established.
The insect is known in Australia as the world's worst fruit pest; it lays eggs in mature fruit and the maggots destroy the fruit from the inside.
Horticulture New Zealand says the pest is regarded as the biggest threat to the $4 billion export industry, because of the damage it can do to a wide range of fruit and vegetables and the disruption to trade.
Chief executive Peter Silcock says growers are very concerned by the find, which has occurred in the middle of the fruit export season.
He said the discovery of fruit fly in the 1990s cost the Government $10 million and led to increased screening costs for the horticulture industry as well as restricted access to some export markets for a time.
Minister of Primary Industries David Carter told Morning Report there are no indications at the moment that any country might ban New Zealand products.
He said the insect may have entered the country on fruit imported from Queensland or on fruit in an airline passenger's luggage.
Export disruption only likely if more fruit flies found
Mr Carter says serious disruption to fruit and vegetable exports is only likely to occur if more fruit fly or evidence of breeding populations are found.
Philip Bird of exporter Integrow Marketing says while news of the discovery will spread quickly through the worldwide industry, most countries will take no action and only a few may be "more kneejerk" in their reaction.
The ministry has increased surveillance measures in Auckland, checking properties and setting more traps.
If more insects are discovered an eradication programme may have to be carried out, as happened when two Mediterranean fruit fly were found in Auckland in the 1990s.
The Queensland variety of fruit fly has been found in New Zealand twice before, in Northland in 1995 and in Auckland in 1996, but has never become established.
Ministry deputy director general compliance and response Andrew Coleman says it is hoped the discovery will not affect fruit exports, however trading nations make decisions based on their own rules and regulations.
"We're hoping that they understand the assurances that we're able to provide, we are very active in our response, we've got traps being monitored, we've got new traps being set up."
Mr Coleman says it could take days or weeks to find out whether any more insects are present.
He said the most likely way fruit fly can arrive in New Zealand is in fresh fruit.
Since 2006, the ministry has intercepted species of fruit fly more than 50 times in border inspections.