True fruit flies are one of the world’s worst pests of fruit and fruiting vegetables, causing millions of dollars worth of damage each year.

While Australia has a number of native pest fruit flies of its own, some exotic fruit fly species present in neighbouring countries are also of great biosecurity concern. Their introduction and establishment would cause significant additional economic damage and trade disruption, as well as requiring expensive eradication campaigns.

Australia has an extensive fruit fly surveillance program with traps in more than 1,600 locations across the country. Early detection of exotic fruit flies is the best means to achieve prompt and cost-effective eradication in the event of an incursion. The trapping program also provides evidence to overseas trading partners of Australia’s freedom from particular fruit fly species. Part of surveillance, however, is the ability to accurately diagnose the flies detected, and unfortunately this is not easily done for all offshore pest species, especially those belonging to the Oriental fruit fly (Bactrocera dorsalis) complex.

The Oriental Fruit Fly complex contains several species, including B. dorsalis, B. papayae and B. philippinensis, which are capable of causing significant damage to commercial crops in Australia. Unfortunately, robust diagnostics for these species do not currently exist. Even worse, it is not currently possible to separate these pests from endemic, non-regulated fruit flies.

Queensland University of Technology’s (QUT) Associate Professor Tony Clarke is leading a CRC project which will undertake a detailed biological, morphological and molecular study of the pest flies in the B. dorsalis complex, to confirm species boundaries and develop new methods for their diagnosis.

This project has received international interest from the International Atomic Energy Agency (IAEA) of the United Nations Food and Agriculture Organization (UN/FAO). In early July, project members Tony Clarke, QUT based CRC postdoctoral fellow Dr Mark Schutze and Lincoln University’s Dr Karen Armstrong, were three of only 11 people worldwide invited to participate in an international consultants meeting held at the United Nations' IAEA headquarters in Vienna, Austria. 

During the meeting, global fruit fly experts discussed a proposed new international project on resolving fruit fly species complexes, with a focus on the B. dorsalis complex and the South American Anastrepha fraterculus complex. The project will develop strategies to resolve species boundaries in fruit flies and has applications for sterile insect technique programs and trade. The role of the UN/FAO’s IAEA is to help member nations facilitate trade and improve agricultural and horticultural industries through the non-military use of nuclear technologies.

Pending likely UN/FAO IAEA approval, this project will run for five to six years and involve strong collaborations between Australian and international fruit fly research groups.