Using a plane to drop millions of fruit flies into a quarantine zone might seem a strange way of containing an outbreak of the pest, but authorities say it's a "game changer".

Key points: Sterile flies have been dumped over Woodville Park, Woodville Gardens, Kilkenny and Athol Park

Sterile flies have been dumped over Woodville Park, Woodville Gardens, Kilkenny and Athol Park Queensland fruit fly costs the Australian horticultural industry about $300 million every year

Queensland fruit fly costs the Australian horticultural industry about $300 million every year Several outbreaks have been declared in suburban Adelaide in recent years

Two million of the "irresistible" and sterile fruit flies have been airdropped over parts of Adelaide, in a bid to eradicate female flies from a recent outbreak.

So what started this?

The program has been in the works for some time.

This release is targeting Queensland fruit flies detected in the north-western suburbs in January this year.

Eight flies and larvae were detected near Woodville Gardens, prompting import restrictions on damaged fruit coming from Queensland.

It sent several suburbs into a biosecurity lockdown, preventing the removal of any fruit from the quarantine zone.

How does it work?

The sterile fruit flies were bred in the state-of-the-art National Sterile Insect Facility at Port Augusta in regional South Australia.

There, Queensland fruit flies are bred in labs and sterilised with X-rays.

The sterile flies are then released into areas with wild populations to breed with wild females.

The wild female flies eventually become outnumbered and die out.

What are they doing with this run in Adelaide?

In response to the outbreak, sterile flies have been pumped from a plane over several suburbs including Woodville Park, Woodville Gardens, Kilkenny and Athol Park.

Not only are the flies sterile, they have also been given a better chance of scoring a mate.

They've been given supplements to make them sing better, smell better and seem fitter to their female companions.

The aim is to encourage the fertile female fruit flies to choose sterile ones as mates, and ultimately preventing them from reproducing.

Map showing the quarantine area following the fruit fly outbreak in Adelaide's north-western suburbs. ( PIRSA )

South Australia's Agriculture Minister Tim Whetstone said the technology was important in the fight against the potentially-devastating pest.

"This is an absolute game-changer, not only for South Australia's horticulture, but for the nation's exporters," Mr Whetstone said.

"Creating more jobs, making sure that South Australia and the nation is fruit-fly free.

"What we've seen at Port Augusta, the breeding of these sterile flies is just a small step in the big picture to make sure that here in South Australia we lead by example."

Hort Innovation chief executive John Lloyd said the breeding technology used in Port Augusta had exciting potential for the future.

"I'm not sure I'm the best person to talk about the sex life of a fruit fly," he said.

"But in all these programs anywhere in the world what they will do is try to breed an elite male line ... and that includes things like certain smells.

"They have to be virile and desirable.

"The thing we would like to do next is get a male-only line so we're not releasing females, which is a bit of a waste."

Why is it important?

Queensland fruit fly costs the Australian horticultural industry about $300 million in fruit and vegetable losses and damage every year.

Several outbreaks have been declared in suburban Adelaide in recent years, while an outbreak of fruit fly in Tasmania in February sparked a state-wide biosecurity alert.

A major outbreak would be disastrous for horticultural areas — including the state's Riverland region — which currently enjoys lucrative "fruit-fly free" status from several of its key export markets.

Federal Agriculture Minister David Littleproud said measures like the sterile fruit fly release were critical to keeping Australia's horticultural industry safe from serious pest damage.

"Being a Queenslander — this is not one of our great exports," he said.

South Australia's Agriculture Minister Tim Whetstone said they wanted to ensure the state remained fruit fly free.

"The damage it does is to... the horticultural regions, but also our reputation (as an exporter)," he said.

"Those [fruit fly] detections send alarm bells right around the state.

"Commodities are reliant on being fruit fly free — it is our market advantage."

"The damage it does not only to the cost of the region's, but what it also does is to our reputation right here in South Australia.

"Today's release is to response to detections early in the year and those detections send alarm bells right round the state."

How will they know whether it's worked?

"Of the four thousand traps that South Australia has, they will be regularly checked and we will see fruit flies that will be the sterile type in those traps," Mr Whetstone said.

"It's really important to understand that the introduced sterile flies will have a dye on them, they will be detectable just by line of sight.

"It's critically important that people monitor, they pick up their dropped fruit, their backyards are clean from any disposed fruit and be vigilant."

He said while two million fruit flies seemed like a big number it was a "a very, very small step in a very big picture".

It will ramp up to 50 million a week.

"This is a significant investment ... a $45 million commitment around tackling this issue that costs the industry around $300 million dollars a year," he said.