Researchers buzzing with latest sterile Queensland fruit fly finding

Scientists have developed an additional safeguard to differentiate factory-reared sterile Queensland fruit flies (Qflies) from their wild relatives in research being delivered as part of the national Sterile Insect Technology Plus partnership (SITPlus).

Macquarie University researcher Dr Polychronis Rempoulakis said in preparation for the release of sterile Qflies into the wild next year as part of the SITplus project, technicians need to be able to tell SIT and wild flies apart to monitor the program’s success.

“Factory flies and wild flies have very different carbon composition due to their differing diets. The SIT flies are reared on a diet containing sugar from cane, while wild flies grow in fruit in nature,” he said.

“So, by measuring what we refer to as their carbon ‘isotope ratios’, a persistent legacy of differences in the carbon found in the sugar cane or fruit they eat as larvae, it’s easy for us to tell them apart as adult flies.”

The testing machine at Environmental Isotopes, a company based at Macquarie University, has been refined over the past two years to reach this milestone.

“This tool has been developed for other species around the world and trialed in an experimental setting, but this is the first time that it has been developed and tested to the point where it can be used operationally,” Dr Rempoulakis said.

While SIT flies are marked with a fluorescent dye that is visible under UV lights, this new technology will allow field officers to test flies in rare incidences where the visible marker may be unclear.

By confirming fly identity in such situations, this new technology can prevent the unnecessary expense of control measures that might be triggered by misidentification of released flies.

“This tool is a safety net that provides a higher level of security and safety for the grower communities that are affected by Qfly and in areas where the SIT program will be used,” Dr Rempoulakis said.

This project has been funded by the Hort Frontiers Fruit Fly Fund, part of the Hort Frontiers strategic partnership initiative developed by Hort Innovation, with co-investment from Macquarie University and contributions from the Australian Government.