Pereira Junior, Amilcar MachadoCamargo-Mathias, M. I. [UNESP]Daemon, E.Peconick, A. P.Lima-Souza, J. R. [UNESP]Oliveira, P. R. [UNESP]Braga, A. S.Lara, L. J.Remedio, R. N.2019-10-062019-10-062019-01-01Natural Product Research.1478-64271478-6419http://hdl.handle.net/11449/187358The activity of carvacrol was evaluated in R. microplus female ticks by estimating the mean lethal concentration (LC 50 ) and the acaricidal efficacy. Ticks were subjected to the Adult Immersion Test (AIT) to calculate LC 50 . From this value, the AIT was performed again at the concentrations of 20%, 40%, 60%, 80% and 100% of the LC 50 . Two control groups were established: one treated with distilled water and one with the solvent (ethanol 50%). The following parameters were evaluated: female weight before oviposition, egg mass weight, pre-oviposition and incubation period, hatching percentage, egg production index, fecundity rate, estimated reproduction, reduction in oviposition and hatching, and product efficacy. The obtained LC 50 was 20.11 mg/mL. Egg mass weight, egg production index, pre-oviposition and fecundity rates of groups treated with 80% and 100% of LC 50 were statistically different when compared to control groups. The product efficacy in groups treated with 100% of LC 50 was 61.10%.engcattlecontrolLC50PhytotherapyticksArtigo10.1080/14786419.2019.1569657Acesso aberto2-s2.0-85061577836