Acaricidal activity of the oil from Jatropha curcas L. seeds on larvae of Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae).

In order to evaluate the acaricidal activity of the oil from Jatropha curcas L. seeds, with different storage periods, against larvae of the tick Rhipicephalus (Boophilus) microplus (Strain: Cayo Coco), this research was conducted at the Pastures and Forages Research Station Indio Hatuey. Oils with different storage periods (1 and 4 years) were evaluated. The oil was obtained from the mature, sun-dried and shelled fruits, of the Cape Verde provenance, collected in the Paraguay Farm, Guantánamo. A complete randomized experimental design was used with 17 treatments and 10 repetitions per treatment, from the different evaluated concentrations for the oils (0,5; 1,75; 2,5; 5 and 10 mg/mL), the solvent (Tween-80) and the negative (distilled water) and positive controls (Butox® Deltamethrin) used. For the in vitro studies the larval immersion techniques were applied. The negative control (distilled water) did not show acaricidal activity on the larvae (2,07 ± 0,40 %); a similar performance was observed in the solvent concentrations. The oil showed a marked larvicidal action in the two storage periods, with significant differences (p<0,05) among the experimental treatments, the negative control and the solvent, with values higher than 93 %. The best results were for the concentrations of 10 mg/mL oil 2014 (97,72 ± 0,58 %) and of 10 and 5 mg/mL oil 2017 (98,99 ± 0,33 and 98,11 ± 0,30 %, respectively), without significant differences with regards to Butox® (97,83 ± 0,45 %). The results showed that the oil from the J. curcas L. seed has acaricidal activity for the evaluated concentrations against larvae of the tick R. (B.) microplus, without significant differences between the storage periods and with values that exceeded 90 % of efficacy.