Millions of Mediterranean fruit fly maggots are being reared each week in Perth, Western Australia, in an effort to eradicate the pest.

It might seem strange, but you have got to breed them to boot them out.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 6 minutes 30 seconds 6 m Rural Reporter: Breeding maggots to kill the flies Download 3 MB

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 5 minutes 40 seconds 5 m WA Department of Agriculture fruit fly breeder Rose Fogliani leads a tour of the breeding facility in South Perth ( Eliza Wood ) Download 2.6 MB

Staff from the Department of Agriculture are ramping up production ahead of an assault on the fruit fly population in Carnarvon, on WA's west coast.

Operations manager Ernie Steiner said Carnarvon had a long history of fruit fly outbreaks.

The pest appeared in 1978 and was eradicated in 1982. By 1984 it was back again.

Despite the history, Mr Steiner is confident it can be eradicated again from the valuable horticulture region.

Department of Agriculture staff Rose Fogliani and Ernie Steiner in the fruit fly breeding facility at South Perth. ( ABC Rural: Eliza Wood )

"The technology that we've got available to us, as compared to 1978, is much better," he said.

"There have been significant improvements in that we can release a male-only strain of sterile fly. That is a huge advantage."

The male pupae are sterilised with radiation.

When they are released into infested areas, they compete with the local males, and unsuccessfully mate with the females.

The female fruit flies lay their eggs through a fine screen on the outside of their cage. ( ABC Rural: Eliza Wood )

Mr Steiner said staff had recently completed a detailed map of Carnarvon's growing area, and recorded all the host plants.

This would tell them where to release the sterilised males.

"We're overwhelming the existing male fruit fly population — they'll hardly get a look-in for mating," Mr Steiner said.

"Our sterile flies will out-number the wild fly population by hopefully 100 to one."

The breeding facility looks like a basic shed from the outside, but inside it is a rabbit warren of rooms containing the whole life cycle including the egg layers, the hatching maggots, and the pupae.