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Choosing the right chemical

Chemicals can be used strategically to reduce the risk of flystrike.

The table below summarises the different classes of chemicals that are available for both preventing and treating flystrike.


In many instances the choice of chemical product will determine how the product must be applied to the sheep. Dicyclanil, for example, is only available as a spray-on product. Other insecticides may be available in several formulations and producers must choose products and application methods that suit their purpose. For example, cyromazine is available as a jetting fluid/dip concentrate that must be diluted in water prior to use; or as a ready-to-use spray-on product.

Only one product (Extinosad Lice, Fly and Maggot Eliminator) containing spinosad is registered for protection against flystrike and will provide at least 8 days protection on mulesing and other wounds and up to 4–6 weeks protection when jetted onto adult sheep. This product is also considered an allowable input on organic properties accredited under the Australian Certified Organic standard, but this certification does not extend to other programs. Other spinosad products are for treatment of flystrike (rather than prevention) and treatment of lice, and are not recognised by organic programs. Always read the label to ensure you are using the correct formulation for the job at hand.

The most common application techniques are hand jetting, automatic jetting races, spray-ons and plunge or shower dipping. Dipping should only be regarded as an emergency flystrike treatment. The advantages and disadvantages of the various application techniques are compared in the following sections. Information is provided on best practice for dipping, jetting and spray on application in downloadable documents.

The FlyBoss tools provide a detailed list of flystrike and lice treatment products currently available. The tools also provide details on

The list can be sorted by application method. When applying flystrike and lice chemicals ensure that you are compliant with the Wool Harvesting Interval (WHI), Export Slaughter Interval (ESI) and Meat Withhold Period (WHP) relevant to the particular chemical. Failure to comply risks key markets for wool and meat products and the safety of workers and consumers.

The FlyBoss tools can also be used to assess the effectiveness of a particular chemical application in reducing risk within the flock. Use the FlyBoss tool to compare different management scenarios and optimise chemical treatments.

For detailed notes on chemical groups download the following documents.

  • Organophosphates
  • Insect Growth Regulators
  • Ivermectins

DownloadOrganophosphates (17 KB)

More information relating to chemicals registered to treat lice and flystrike: