Sheep Ectoparasite Resistance Update

The impact of insecticide resistance on blowflies is usually a reduction in the protection period provided by treatments rather than complete control failure. The blowfly that initiates most flystrike in Australia is Lucilia cuprina which has developed widespread, high-level, stable resistances to insecticides like the organophosphates. This project investigated six insecticides registered for flystrike control, including diazinon; ivermectin; spinosad; imidacloprid; cyromazine and dicyclanil in order to provide up to date information on the presence and level of resistance and its distribution across the sheep producing areas of Australia.