Vol. 9, Issue 2, Part H (2024)

Author(s): Patel MK, Parsani HR and Shyma KP

Abstract: Rhipicephalus microplus is the most common tick species in India infesting cattle and buffaloes and causing significant economic losses to dairy and leather industries by adversely affecting the milk production and quality of hides. A study to evaluate the acaricide resistance status of Rhipicephalus microplus to fenvalerate and flumethrin was conducted on the samples collected from organized and unorganized farms of mahesana district from Gujarat state, where treatment failures were reported frequently. Adult Immersion Test (AIT) was conducted using field strain for determination of 50 and 95% lethal concentration of fenvalerate and flumethrin. Results obtained by the AIT showed level I resistance (RF > 5), level Ⅱ resistance (5.1 < RF < 25) and level Ⅳ resistance (RF > 41) has been developed against both fenvalerate. Carboxyl esterase essay was also performed for understanding the mechanism of resistance in R. microplus against the synthetic pyrethroid compounds. Quantitative analysis of α and β- esterase enzyme activity was found to be in range of 2.01±0.221 to 13.85±0.141 and 1.79±0.056 to 4.89±0.102 μmol/min/mg of protein, respectively. RF was high (Punjpur village of Danta taluka) having α-esterase and β-esterase were 13.85±0.141 and 4.89±0.102 μmoles/min./mg, respectively which indicated RF correlate with the enzyme activity and also in some villages had the RF was low but enzyme activity was high. This may be due to present strain may be treated with other group of synthetic pyrethroids

DOI: 10.22271/veterinary.2024.v9.i2h.1256