An Appraisal of Ruelene and Trolene Against Cattle Grub Infestations, (Oestridae: Diptera)

Abstract

The reductions in numbers of cattle warble grubs produced by Ruelene and Trolene in a heavily infested cattle herd were compared. Ruelene intramuscular injections at 5 mg./kg. and 10 mg./kg. and Trolene boluses at 105 mg./kg. reduced the numbers of grubs by 83, 86 and 86 per cent, respectively. Statistically these reductions were not significantly different. The intramuscular injections did not cause detectable lesions at the injection site in the 90 calves treated. The injection method was preferred to the bolus method for ease of administration, economy of labour, and decreased danger of injury to animals. Feeding Ruelene at 5 mg./kg. and 10 mg./kg. daily for 5 days, and feeding Trolene at 15 mg./kg. daily for 7 and 12 days, reduced the numbers of grubs by 95, 94, 94 and 97 per cent respectively. These reductions were not significantly different.