Horticulture New Zealand says the Government must reinstate the X-raying of all air passengers' bags as they enter the country.
The organisation says a Queensland fruit fly found in Auckland suburb of Avondale last week shows cuts to biosecurity are undermining the protection of the country's primary industries.
Following a foot-and-mouth outbreak in Britain in 2001, X-rays were increased to examine the bags of all incoming air passengers.
Horticulture New Zealand president Andrew Fenton says that has been replaced in the last 18 months with a policy to speed things up for travellers.
He says frontline biosecurity staff have been reduced since 2007 by 38 to 280, while passenger numbers increased.
Mr Fenton also says there have been no sniffer dogs at Wellington International Airport since September last year.
An outbreak would cost New Zealand exporters billions of dollars - far more than the cost of increased monitoring, he warns.
But the Ministry for Primary Industries says reinstating X-ray checks of all baggage would not necessarily have stopped the Queensland fruit fly.
Andrew Coleman, a deputy director-general at the ministry, says airport security is only one way to prevent biosecurity threats from entering the country.
Mr Coleman says it was a surveillance system that discovered the fruit fly in the past week and focusing entirely on airport systems might not be the best protection.