Status of Acetylcholinesterase Mediated Organophosphate Resistance in Cattle Tick, Rhipicephalus Microplus (Acari: Ixodidae)

Abstract

INTRODUCTIONThe ticks are significant blood sucking ectoparasites affecting domesticated animals causing serious threat to the livestock industry, especially in tropical and sub-tropical regions. Heavy tick infestations cause severe economic losses directly through anorexia, toxicosis, decreased milk production and weight gain, damage to hide, treatment costs and indirectly by increased mortality due to tick-borne infections. The estimated annual cost of management of tick and tickborne diseases (TBDs) in livestock globally is US$ 14000-18000 million and of India is US$ 498.7 million [1]. As per a recent report the annual cumulative loss due to infestation of ticks and TBDs is 61076.46 million INR or 787.63 million USD [2].Presently, control of ticks is predominantly dependent on chemical acaricides, viz., organophosphates (OP), synthetic pyrethroids (SP), formamidines and macrocyclic lactones (ML). Application of these drugs often leads to acaricide resistance, pollution of environment and residues in