Given the increasing resistance to conventional acaricides, the search for plant-based therapeutic alternatives to control the cattle tick Rhipicephalus (R.) microplus has been driven. This tick is responsible for transmitting zoonotic hemoparasites and causing significant economic losses. This study aimed to validate ethnopharmacological reports on the acaricidal effects of plants traditionally used in the state of Meta, Colombia, on R. microplus teleogines and larvae, and to identify groups of secondary metabolites. Ethnopharmacological surveys were conducted, finding seventeen plant species. Eighteen ethanolic extracts were prepared from these species for in vitro evaluation of their acaricidal effect at concentrations of 10, 20, 40, 80, and 160mg/mL. In addition to performing a preliminary phytochemical analysis, adult immersion tests (AIT) and larval immersion tests (LIT) were performed observing mortality and impact on the reproductive cycle. Probit analysis was used to determine LC₅₀ and LC₉₀ values, and ANOVA and Tukey's post-hoc test were used to determine differences between the concentrations of the extracts and the negative (Tween-80 2%) and positive (Cypermethrin 0.015%) controls (P<0.05). When mortality in AIT and LIT was compared between the highest concentration (160mg/mL) of the extracts and cypermethrin, five and three extracts, respectively, showed higher mortality rates (P<0.05). Similarly, eight extracts had significant adverse effects on the reproductive cycle in AIT (P<0.05). The best LC₅₀ and LC₉₀ values ​​were obtained in Annona muricata (AIT=20.74mg/mL and 106.04mg/mL) and Dioclea virgata (LIT=26.80mg/mL and 116.78mg/mL). Of the twelve groups of secondary metabolites evaluated in the phytochemical analysis, alkaloids, coumarins, cardiotonic glycosides, and sapogenins were the most prevalent. Seven promising plants were found for the control of R. microplus. These results confirm the value of traditional ethnopharmacological knowledge and provide evidence of the potential of plant extracts as a sustainable alternative for tick management in cattle.

To Cite This Article: Velasquez-Peña MA, Lesmes-Rodríguez LC and Jaramillo-Hernández DA, 2026. Ethnopharmacological screening of promising medicinal plants with in vitro acaricidal effect on Rhipicephalus microplus in the state of Meta, Colombia. Pak Vet J, 46(4): 910-919. http://dx.doi.org/10.29261/pakvetj/2026.071