RÉSUMÉ
Brazil numerous plant species are used for controlling ectoparasites on cattle. However, the need to consolidatethis popular knowledge through existing chemical characterization of secondary compounds in these plants and theapplication of bioassays able to reveal its biological action observed. For this study, we obtained the essential oilof the Croton blanchetianus by hydrodistillation and their chemical compounds identified by gas chromatographycoupled with mass spectrometry. The major chemical constituents stood out as eucalyptol (16.9%), β-caryophyllene(15.9%), and germacrene-D (14.5%). Various concentrations of the C. blanchetianus essential oil were used inorder to test their biological action on the cattle tick Rhipicephalus (Boophilus) microplus. There was a significantacaricide efficacy, and the results were statistically significant at a confidence level of 95%.