Eficácia dos óleos essenciais de Lippia Alba e Citrus sinensis (L.) Osbeck e as suas diluições com técnicas homeopáticas para controle do carrapato Rhipicephalus microplus

Abstract

Parasitism by the cattle tick, Rhipicephalus microplus, causes economic losses that exceed $ 3 billion annually to Brazilian livestock. The control of this ectoparasite is based on chemical ticks, usually indiscriminately, resulting in undesirable consequences such as animal and human poisoning, action on non-target arthropods, environmental pollution and acceleration of the mechanism of selection of resistant strains. Therefore, new control technologies have gained prominence, such as the use of plant bioactives associated with ultra dilution techniques. Thus, the objective of this work was to evaluate the in vitro acaricidal activity of the essential oils of Erva cidreira (Lippia alba (Mill.) NE Brown) and Orange Peel (Citrus sinensis (L.) Osbeck) and ultra diluted preparations by homeopathic techniques of these oils on cattle ticks. Larval Pack Tests (LPT) and Adult Immersion Test (AIT) were performed, the latter being performed only with essential oils. In LPT, the larvae were exposed to the following treatments and controls: essential oils of lemongrass and orange peel at a concentration of 20mg/mL, ultra diluted preparations of these essential oils, using homeopathic techniques produced according to the Centesimal Hahnemannian method in the potencies of. 6CH, 12CH and 30CH and as controls were used a group with distilled water and Tween 20 at 20mg/mL and another with 70o alcohol. The parameter evaluated was the percentage of mortality verified 24 hours after treatment. At AIT teleogins were immersed for five minutes in the following treatments and control: essential oils of lemongrass and orange peel at a concentration of 80mg/mL and a control group with distilled water and Tween 20 to 30mg/mL. The evaluated parameter was the control percentage analyzed through the reproductive activity of the females. The treatment means of each test were compared by analysis of variance (ANOVA), followed by Tukey test (p <0.05). Mortality rates of larvae treated with Erva cidreira and Orange Peel essential oils were 5.94 ± 0.07 and 4.54 ± 0.03, respectively, and the water control group was 1.45 ± 0.01, respectively, while in the oil dilutions at 6CH potency, they were 99.24 ± 0.02 and 75.50 ± 0.23, respectively and the alcohol control group was 2.72 ± 0.03. In the other potencies in the larval mortality was observed. In AIT, Erva cidreira essential oil showed a high percentage of control 93.7%, differing statistically from the others. From these results it can be concluded that Erva cidreira essential oil has high acaricidal action on R. microplus females, and its diluted product in potency 6CH also has acaricidal effect and therefore has relevance for further studies.