Vol. 9, Issue 10, Part B (2025)

In Nagpur district of Maharashtra State, deltamethrin is the most commonly used acaricide for tick control in livestock. The research aimed to assess deltamethrin resistance in ticks infesting cattle following complaints from livestock owners regarding the diminished efficacy of deltamethrin in several areas of Nagpur district, Maharashtra. This study evaluated the efficacy of deltamethrin against ticks infesting cattle by investigating deltamethrin resistance in ticks from five talukas of Nagpur district of Maharashtra state using in vitro method, specifically the adult immersion test (AIT). Commercially available deltamethrin at five distinct concentrations; 25 ppm, 50 ppm, 70 ppm, 105 ppm and 200 ppm were used to assess the resistance through AIT. Based on criteria like adult mortality, reproductive index, oviposition inhibition and egg hatchability of treated female ticks, Rhipicephalus microplus female ticks from all five talukas of Nagpur district in Maharashtra were resistant to all the concentrations of deltamethrin compared with control group treated with distilled water with no significant difference. The findings in the current study revealed that Rhipicephalus microplus ticks infesting cattle in Nagpur district of Maharashtra state had high levels of deltamethrin resistance.