Increase in SIT locations across the Riverland

The world leading program is an effective weapon in the fight against fruit fly and is usually implemented following on-ground eradication activities including baiting, ground treatments and spraying with the aim of targeting any remaining fruit flies in an outbreak area.

These combined activities, along with efforts by local growers and residents against the pest, are yielding promising results in the Riverland as over half of the Queensland fruit fly (Q fly) outbreak areas in the region have not recorded a new fruit fly detections in the last three months.

SIT pupae are collected and irradiated at PIRSA’s Port Augusta SIT Facility before being transported to the rear out facility in Barmera, where they are then reared to sterile flies before being released across the outbreak areas.

Once released from the plane, the sterile Q flies will then breed with any remaining wild Q-flies thereby disrupting the Q-fly life cycle.

Jason Size, Incident Controller Fruit Fly Emergency Response, said the success of the SIT program relies on low wild fly population numbers, hence being used as a response tool after on ground eradication activities had finished.

“You want the wild fly population to be at a level than when SIT flies are released, they easily outnumber the wild fruit fly population, making it difficult for. wild Q-flies to actively search out other flies to mate with, impacting the breeding cycle.

“The increase in the number of locations we are now releasing SIT flies reflects our eradication efforts. As there have been no new detections in 22 outbreaks or over half of our outbreak areas since 16 December, this really tells us that what we are doing is working.

“This is a huge milestone in the fight to eradicate Queensland fruit fly.”

John Trappel, PIRSA SIT Rear Out Facility Manager, explained the outnumbering of the wild Q-fly population during SIT releases to crowd control.

“It’s like going to a football game to meet a friend,” he said “If you’re there and no one else is around, you will more than likely find your friend – and in our instance another wild and fertile fly – easily.

“But if you put millions of people in the same area at once – as we do with a SIT release – it’s very unlikely you’d be able to meet up. becomes unlikely that a fertile wild Q-fly can find a mate.”

Detections and sterile fly releases

For the 12-week period from 23 December to 16 March, this is how many outbreak areas that Queensland fruit flies were found in Riverland (as of 24 March 2025):

• No flies were detected in 22 of the 56 outbreak areas.
• Flies were detected in 34 of the 56 outbreak areas.

PIRSA will release sterile flies at the following locations until 12 May 2025.

• Barmera
• Berri
• Bookpurnong
• Cobdogla
• Glossop
• Gurra Gurra
• Holder
• Loveday
• Loxton North A
• Lyrup
• Monash, Monash North
• Murtho C, D, E, F
• Overland Corner
• Pike River, Pike River West
• Taylorville
• Winkie

see Sterile Insect Technique for more information.

Outbreak end dates

The end dates for all outbreaks are as follows:

• Riverland: 20 November 2025
• Ceduna: 24 October 2025
• Glynde: 19 October 2025
• Salisbury: 9 May 2025

Contact

For more information about fruit fly, self-baiting, or the latest outbreak advice, visit fruitfly.sa.gov.au or call the 24-Hour Fruit Fly Hotline on 1300 666 010.

PIRSA Family and Business (FaB) mentors are available to support Riverland residents through this challenging time. FaB mentors are available for a free, informal, confidential, and independent conversation in person or over the phone. Riverland and Murraylands FaB mentors include:

• Robyn Cain – 0411 633 085
• John Chase – 0419 848 672
• Brent Fletcher – 0439 409 430.