Semi-field studies, using the larval implant technique, show that sheep may be protected against resistant larvae of Lucilia cuprina by thorough jetting with chlorfenvinphos, diazinon, dichlofenthion and fenthion ethyl, but not bromophos ethyl, for the normal duration of waves of bodystrike in New South Wales. The standard method of assessing implant data is to be preferred to analyses based on average protection due to the extra time required for the latter procedure.
