Though she was only about eight millimetres long and weighed less than a gram, the female had the potential to destroy much of the regions' fruit, which could have cost Victoria millions of dollars in lost earnings and the potential loss of many jobs.

She was a Queensland fruit fly, one of the most destructive pests in Australia. In January she was found in one of the region's 2000 pheromone-laden fruit fly traps. The operation to find and eradicate any other interlopers was swift and massive, including a 15-kilometre exclusion zone and up to 100 staff, many drafted in from other divisions across the state. Only one other fruit fly was found, a male.

The Department of Primary Industries estimates that up to 700 grape and fruit growers within the exclusion zone were directly affected by the crackdown.

The region's table grape growers say they have lost ''many tens of thousands of dollars'' in treatment costs and lost exports and are calling on the state government to step up protection measures, such as 24-hour roadblocks to check incoming vehicles for fruit flies.

But not everyone agrees. ''I don't think it would achieve a hell of a lot,'' senior fruit fly policy officer at the Department of Primary Industries Gary D'Arcy said.

Just one permanent roadblock would cost about $1 million a year, he said, adding that the money would be better spent on public awareness.