Australian Wool Innovation (AWI) senior research manager Carolina Diaz announced on July 14, 2026, that scientists have developed a new biopesticide for the sheep industry using tea-tree oil combined with nanotechnology. This innovation aims to prevent and treat flystrike, a painful blowfly infestation affecting sheep, particularly on their backsides.

Flystrike is traditionally managed with chemical insecticides, but resistance to these chemicals has been identified across all wool-producing states in Australia. Tea-tree oil is known to kill and deter insects and has been used on humans for lice treatment and on pets for tick control, as well as repelling mosquitoes and flies. However, the raw oil's effectiveness on sheep is limited because it lasts only hours due to sensitivity to evaporation and UV radiation.

To overcome this, researchers have encapsulated tea-tree oil inside nanoparticles, which are less than a thousandth of a millimetre in size, allowing for a more persistent delivery of the treatment. "We are finding a way to deliver this [treatment] in a better and more persistent way using nanotechnology," Dr Diaz said. The project was launched 18 months ago in response to the emergence of chemical resistance.

Dr Diaz noted that if the treatment lasts for three to four weeks, it would provide producers with a viable alternative within their rotation system of chemicals. Philip Butlin, chief executive officer of the company supplying the oil, confirmed their involvement in providing tea-tree oil for the biopesticide research and trials.

This natural, essential oil-based alternative is expected to have low residue and not cause long-term resistance, offering a promising new tool for the Australian sheep industry.

Sources