LAUSR

Fipronil is a broad spectrum phenylpyrazole compound which is recently used in field condition for the control of the tick, mites, flea and flies population in domestic animals and pets. It is used more often in organised cattle farms to avoid fly menace and concurrently reduce tick infestation. Repeated exposure of fipronil to cattle ticks, Rhipicephalus microplus and Hyalomma anatolicum might have led to the emergence of acaricide resistance. The objective of this study was to estimate fipronil sensitivity in field ticks collected from 8 different farms of Haryana (India) using FAO recommended larval packet test. Out of these, four cattle farms were found infested with both R. microplus and H. anatolicum ; one farm at Sirsa district of Haryana comprises of H. anatolicum exclusively whereas three other farms at Hisar and Bhiwani districts of Haryana showed only the presence of R. microplus ticks. The resistance factor for H. anatolicum against fipronil in larval packet test ranged from 0.23 to 3.8, whereas, it ranged from 2.4 to 28.2 for R. microplus ticks. The H. anatolicum isolates displayed lower resistance factor in comparison to R. microplus population indicating greater selection on one host tick and faster development of fipronil resistance. This article reports for the first time the emergence of fipronil resistance in Western part of Haryana and highlights the beginning of fipronil resistance in H. anatolicum ticks which is responsible for high incidence of bovine tropical theileriosis in Northern India.