Detoxification as a Mechanism of Resistance I a Strain of the Cattle Tick Boophilus Micropluse (Canestrini) Resistant to Organophosphorus and Carbamate Compounds

Abstract

Strains of the cattle tick resistant to organophosphorus compounds were first found at Ridgelands in central Queensland in 1963 (Shaw and Malcolm 1964; Shaw 1966; Roulston, Stone, Wilson, and White 1968). Resistance of a different type was subsequently found at Biarra in south-eastern Queensland in 1966 (Roulston and Wharton 1967; Wharton 1967; Shaw, Cook, and Carson 1968). Ridgelands and Biarra strains of ticks both exhibit resistance to a wide range of organophosphorus and carbamate chemicals but differ in that resistance levels are higher and resistance extends to a wider range of chemicals in the Biarra strain. Biochemical investigations have shown that resistance in both strains is due to the presence of an acetylcholin-esterase system which is relatively insensitive to inhibition by organophosphorus chemicals (Lee and Batham 1966; Roulston, Schnitzerling, and Schuntner 1968; Schuntner, Roulston, and Schnitzerling 1968)