At the same time, the development of a commercial product tailored to the needs of Australian sheep producers could provide improved markets for tea tree growers who have long battled volatile prices.

The research, conducted by the Rural Industries Research and Develop-ment Corporation (RIRDC) at Gatton, Queensland, in the past three years, found tea tree oil was highly successful in both preventing lice infestations and killing blowfly maggot larvae.

Both lab and pen trials showed a one per cent tea tree oil formulation reliably produced a 100 per cent kill rate.

The research was funded 50:50 by RIRDC and Northern Rivers growers Paul and Pat Bolster, who have more than 100 hectares under tea tree on low-lying coastal alluvial and sandy soils at Chinderah, near Tweed Heads.

The Bolsters have patented the formulation, with the view to eventually supplying the oil used in a commercial insecticide.

Under the research, led by Dr Peter James from the Queensland Alliance for Agriculture and Food Innovation, the two-week shorn sheep were inspected at two, six, 12 and 20 weeks after being dipped and treated no lice were found in the wool.

“We also tested sheep with longer wool and the results showed by jetting both 1pc and 2pc tea tree oil formulations louse numbers reduce by 94pc, in comparison to controls at the two weeks after treatment,” Dr James said.

The laboratory-based flystrike research used formulations consisting of 1pc tea tree oil which reliably led to a 100pc kill rate of first stage maggots.

The research also showed tea tree oil had a strong repellent effect against adult flies, which prevented eggs being laid on the wool for up to six weeks.

With its antibacterial properties and wound healing effects, tea tree oil could also be effective as a preventative treatment for wounds caused by mulesing or tail docking, he said.

The next step, due to start during the next shearing season across three States, is a five flock trial, with each flock of 1000 head dipped in the formulation and monitored.

Mr Bolster said because tea tree oil was a multi-component substance, the prospect of lice building up resistance was very small.

Both men said getting the formulation exactly right was vital and something that would require more research.

“It’s not as simple as mixing tea tree oil with water and applying it to your sheep; it’s a complex and exact science,” Dr James said.