In vitro evaluation of effectiveness of synthetic pyrethroids against brown dog tick

Rhipicephalus sanguineus, the brown dog tick, is one of the most cosmopolitan ixodid ticks of veterinary and public health importance. The domestic dog is the main host of R. sanguineus, but occasionally, can infest a wide range of domestic and wild hosts, including humans. It causes debilitating effects due to blood losses in affected animals and also transmits several pathogens such as Ehrlichia canis, Babesia canis, Haemobartonella canis and Hepatozoon canis. Engorged female R. sanguineus kept for oviposition. Hatched larvae of Rhipicephalus sanguineus were subjected to larval packet test (LPT) to know its efficacy against deltamethrin and cypermethrin. The LC50 and LC95 concentrations were calculated by plotting regression curve of mortality against different concentrations of acaricides. A dose dependent increase in larval mortality was observed for both cypermethrin and deltamethrin. LC50 and LC95 for both deltamethrin and cypermethrin are calculated to be 9.59, 75.87 and 7.08, 219.85, respectively. The results indicated that R. sanguineus ticks were susceptible for cypermethrin, having high percentage mortality at the recommended concentration (200 ppm). However, deltamethrin produced a lower level of mortality at its market recommended dose (25 ppm).