SIT trial for coddling moth underway in Tasmania
For the first time in Australia, a form of fertility control is being trialled to manage a major pest to the apple industry, codling moth.
Researchers at the Tasmanian Institute of Agriculture (TIA) are partnering with local apple growers to pilot a controlled sterile insect technique (SIT) release program.
SIT programs work by flooding the wild population of a pest with large numbers of sterile males to substantially reduce the number of fertile eggs produced. When this is repeated over a number of seasons, the population crashes and infestations drop below damage threshold levels.
According to TIA researchers, SIT has enormous potential to change the way codling moth is managed in Australian apples, particularly when used in tandem with other integrated pest management (IPM) methods.
TIA Senior Research Fellow, Dr. Sally Bound, leads the pilot program which is taking place across three apple orchards in Tasmania’s Huon Valley.
“The moths can mate with each other, but they don’t produce viable eggs and there is no off-spring produced, so it interrupts the lifecycle,” said Bound. “When this is repeated over a number of seasons, the population crashes and infestations drop below the threshold levels set for pesticide application, meaning growers no longer need to apply pesticides for codling moth, even for export markets that require pest free shipments.”
The program is importing sterilized moths from Canada for release in the test orchards. The research team rigorously monitor the moths’ progress using specific pheromone traps. The method is currently used to manage Queensland fruit fly on the mainland.
SIT technology has been successfully used in Canada with an area-wide approach reducing wild codling moth populations by 94 per cent. They also reduced their chemical use for codling moth by over 96 percent. Additional sterile insect release programs have been undertaken in New Zealand (since 2014), U.S., Argentina, Chile, Brazil, South Africa, Morocco, Tunisia and Pakistan.
Bound said the project team will be repeating the program next season. “By the end of the second release season we hope to see a reduction in the numbers of wild moths. It can take a few seasons to see a significant drop off in the wild population.”
The project is a partnership between TIA, the Tasmanian Government, Fruit Growers Tasmanian, The Department of Agriculture, Fisheries and Forestry, the South Australian Research and Development Institute and Lenswood Coop in South Australia. TIA is a joint venture of the University of Tasmania and the Tasmanian Government.
Photo: The presence of external frass is a sign of infestation by the codling moth. Photo: Michele Buntain, University of Tasmania
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