Acetylcholinesterase Insensitivity in the Biarra Strain of the Cattle Tick Boophilus Microplus, as a Cause of Resistance to Organophosphorus and Carbamate Acaricides

Abstract

The penetration and metabolism of diazinon in cattle tick larvae of the susceptible Yeerongpilly strain and of the organophosphorus- and carbamateresistant Biarra strain showed no difference that could account for the resistance of the Biarra strain to this acaricide. Several compounds known to synergize the effect of carbamates against houseflies did not increase the toxicity of carbaryl to larvae of the Biarra strain, suggesting that detoxification was not a factor in resistance.