FOLLOWING on from a wet spring, SA farmers are being warned of a potentially big fly season ahead.
For Cleve farmer Mark Hannemann, the investment is worthwhile to ensure the optimum health of his sheep.
Mr Hannemann farms with his wife, Andrea, and their son, Matt, on their 2000-hectare property north of Cleve, running 1200 breeding ewes, half in a self-replacing Merino flock, and the other half are a White Suffolk cross.
Shearing is done on an annual basis in September, with lambing in April/May after a November joining.
Sheep are treated for lice and flies off shears with AVENGE + FLY, rotated with other products to avoid chemical resistance.
Mr Hannemann considers himself fortunate that he can take a precautionary approach to fly and lice control.
"For us it's mainly flies that can cause a problem, lice are not a big issue as we don't often buy sheep in, our paddocks are clean and our neighbours have clean sheep," he said.
"Certainly, when we do buy sheep in, the first thing we do is treat them for lice before they can spread."
A recent study by Australian Wool Innovation and the NSW Department of Primary Industries, found that chemical resistance to dicyclanil and cyromazine was widespread in Australia.
Chemical resistance has been on the Hannemann's radar for the past 10 years, and they have been rotating their lice and fly management products since.
Until recently, farmers have been able to apply a chemical treatment that has got them through the main flystrike season.
But increasing dicyclanil resistance may rapidly change the landscape for treatment options, particularly for resistance impacted producers.
The Australia-wide study tested all the major blowfly preventative chemical groups to determine their resistance profiles. It found 73 per cent of submissions received across Australia showed resistance to both dicyclanil and cyromazine, whilst a further 15pc of submissions showed resistance to cyromazine.
Troy Animal Health marketing manager Craig Lyons said that though chemical resistance wasn't widespread across all of Australia, mitigating risk of it occurring should be a key consideration for producers as they place orders and head into this high-risk period.
"Studies like this one by AWI & NSW DPI are important to keep farmers informed of how the effectiveness of flystrike control products are changing over time and the importance of integrated pest control," he said.
"We've seen widespread resistance develop to valuable chemicals, and this reminds us of the importance of rotating chemical groups used for fly prevention, and ensuring producers are familiar with the different treatments for flystrike.
"Reductions in the length of protection periods to some chemicals means it's critical farmers are planning their flystrike management."
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