Control of fly strike in sheep by means of a pour-on formulation of cyromazine

Cyromazine, a triazine insecticide, was used as a pour-on preparation to prevent blowfly myiasis in sheep kept in pairs of neighbouring farms in two locations. In 1987 one of the farms in each location used conventional dipping with a diazinon dip while the other used the pour-on treatment. The results achieved with the pour-on preparation compared favourably with the results of conventional dipping and the incidence of blowfly strike was substantially lower than the proportion affected among the untreated groups on the same farms. The 1988 trial results confirmed the efficacy of the pour-on treatment for up to 13 weeks and that retreatments at eight-weekly intervals could reduce the incidence of fly strike to zero.