The biosecurity minister says there is a potentially serious biosecurity threat, with the discovery of a Queensland fruit fly in the Auckland suburb of Mt Roskill.
The fruit fly 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.
David Carter says the Ministry of Primary Industries is working to minimise any adverse trade reaction and is starting to notify New Zealand's trading partners.
The ministry says the Queensland fruit fly infests about 100 species of fruit and if it established itself there would be serious consequences for the country's horticultural industry.
The ministry's deputy director of general compliance and response, Andrew Coleman, says response teams will search Mount Roskill for further signs of infestation.
Staff will need to find out if it is a single insect or if a breeding population has been established in which case an eradication response would be started immediately.
The fly has been found in New Zealand twice before; in Northland in 1995 and in Auckland in 1996.