Acaricidal activity of different solvents on engorged females and larvae of Rhipicephalus microplus

Cattle ticks cause economic losses to the cattle industry in Brazil. The use of phytotherapics as acaricides has shown efficacy of the control of these parasites. In the present study, the in vitro efficacy of the following drugs was evaluated: dimethyl sulfoxide (DMSO), ethanol, methanol, propylene glycol and polyethylene glycol sorbitan monolaurate at dilutions 100%, 20%, 10%, 5%, 1% e 0.5%. The toxic effect of these solvents on engorged female and larvae of Rhipicephalus microplus was analyzed. The immersion test was used to define the reproductive efficiency of engorged R. microplus females and efficiency of the drugs. The immersion test larvae modified syringe was used to analyze of the susceptibility of tick larvae. Propylene glycol and DMSO was used on engorged females and DMSO, ethanol, methanol and propylene glycol, all at concentration of 0.5%, were use on larvae the, showed the lowest mortality rate; this indicate that its use at low concentrations as solvent acaricide in the control of R. microplus could be recommended.