SUSCEPTIBILITY OF RHIPICEPHALUS SANGUINEUS SENSULATO (S.L.) LATREILLE (ACARI: IXODIDAE) TO CYPERMETHRIN, IVERMECTIN, AND AMITRAZ

Abstract

Chemical acaricides, viz. amitraz, cypermethrin, and ivermectin have been in use for control of ectoparasites (particularly ticks) in domestic animals over the past two decades. The present study aimed to appraise the acaricidal effects of ivermectin (IVM), amitraz, and cypermethrin against brown dog tick Rhipicephalus sanguineus sensulato (s.l.), by in-vitro bioassay based susceptibility tests, viz. larval immersion test and larval packet test. Lethal concentrations (LC50 and LC95) values of acaricides were ascertained by applying regression equation analysis to the probit transformed data of mortality and resistance factors (RF) were determined. LC50 values of 11.39, 22.51, and 10.75 ppm, and LC95 values of 57.06, 78.74, and 50.28 ppm were estimated for amitraz, cypermethrin, and ivermectin, respectively. The susceptible status against amitraz and ivermectin whereas, the resistance of level I against cypermethrin was recorded in the study. The present study is the only report of resistance to cypermethrin in R. sanguineus (s.l.), ticks from this region.

Keywords

• acaricides
• brown dog tick
• susceptibility