Acaricide activity of the Ximenia americana L. (Olacaceae) stem bark hydroethanolic extract against Rhipicephalus (Boophilus) microplus

Ximenia americana L. is popularly known as a plum or wild plum, which belongs to the Olacaceae family. Rhipicephalus (Boophilus) microplus represents one of the most important bovine ectoparasites that causes damage to the livestock sector. The objective of this study was to evaluate the acaricide effect of the X. americana stem bark hydroethanolic extract (EHXA) against R. (B.) microplus and its possible modulatory action when in association with cypermethrin, through the adult immersion test. The in vitro acaricide activity of the extract over R. (B.) microplus engorged females was tested using concentrations ranging from 5 to 80 mg mL(- 1), which resulted in mortalities between 13.34 and 100 %, with a posture index (PI) between 0.038 and 0.226 and a posture inhibition index (PII) between 0.87 and 83.33 %. The modulatory effect of the EHXA (1.58 mg mL(- 1)) resulted in mortality between 0 and 46.6 %, with a posture index of 0.221 to 0.139 and a posture inhibition index between 3.01 and 38.49 %. The acaricide activity of the EHXA and its action on oviposition was demonstrated for the first time in this study, demonstrating the potential use of this extract as an auxiliary therapy in R. (B.) microplus control.