detection of deltamethrin resistance in cattle tick, rhipicephalus microplus collected in western haryana state of india

Background: out of 931 species of ticks, rhipicephalus microplus is the most widely studied tick species due to its pivotal role in transmission of babesiosis and anaplasmosis, resulting in huge economic loss in cattle and buffalo’s industry. chemical control using deltamethrin forms the mainstay of tick control strategy because of high potency and low toxicity. however, inadvertent use of deltamethrin has led to the development of deltamethrin resistance in field ticks methods: the engorged female ticks were collected in a plastic container covered with a cotton plug from 10 places (jarwa, barwa, khajakhera, banisi, nakipur, dhangar, badopal, shivalya dharamshala, siwani and meham) of five districts of western haryana. the larval packet test (lpt) was conducted for the characterization of resistance in field tick. results: in the present study, ticks were collected from 10 places from 5 districts of western haryana and evaluated against deltamethrin using larval packed test. the lc50 values (confidence interval) of ticks larvae against deltamethrin collected from nakipur, dhangar, barwa, badopal, shivalya dharamshala, siwani, jarwa, khajakhera, meham and banisi are 73.6 (67.2–81.9), 61.2 (61.6–98.5), 52.7 (14.4–101.0), 140.0 (86.7–448.6), 65.8 (37.1–95.2), 232.1 (201.0–304.7), 3.72 (0.20–9.87), 21.3 (12.0–31.6), 107.6 (96.8–127.6), 54.2 (43.4–58.4) ppm, respectively. the resistance factor ranges from 0.31 to 11.86, indicating variable resistance among field isolates. conclusion: data generated on deltamethrin resistance status in r. microplus from haryana, india can be used as an indicator for the management of the species in the state.