Deltamethrin resistance in field populations of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) in Jammu and Kashmir, India.

Detection of resistance levels against deltamethrin in Rhipicephalus (Boophilus) microplus collected from six districts of Jammu and Kashmir (India) was carried out using the adult immersion test. The regression graphs of probit mortality of ticks plotted against log values of concentration of drug were utilised for the determination of slope of mortality, lethal concentration for 50% (LC50), 95% (LC95) and resistance factor (RF). On the basis of the data generated on mortality, egg mass weight, reproductive index and percentage inhibition of oviposition, the resistance level was categorised as I, II, III and IV. Out of these six districts, resistance to deltamethrin at level I was detected in one district (RF = 1.9), at level II in two districts (RF = 7.08-10.07) and at level IV in three districts (RF = 96.08-288.72). The data generated on deltamethrin resistance status will help in formulating tick control strategy in the region.