Efficacy of chitosan supported organic acaricide extract from Melia azedarach leaves on Rhipicephalus (Boophilus) microplus ticks

Abstract

The Rhipicephalus (Boophilus) microplustick control is mainly performed by chemicals products, but organic acaricides use has higher advantages compared to conventional products. Brazilian cerrado native plants are known for their bioactive potential. Due to this fact, the objective of this study is to evaluate the acaricide action of native cerrado specie, Meliaazedarach, known as Santa Barbara in the tick control. Also, the chitosan nanosphere was evaluated on the extract adsorption and release, as a proposal to raise the acaricide phytotherapic profile. The ethanol extract was obtained by cool extraction from dried leaves of the plant. Chitosan nanospheres were obtained by the phase inversion method. Conductometric titration, ultraviolet-visible ("UV-Vis") and Fourier transform infrared spectroscopy (FTIR) analysis were conducted with materials to evaluate the chitosan anchoring ability. In vitro test was used in engorged females for each treatment, which consisted of control, raw extract and three treatments with increasing concentrations of 0.2; 0.4 and 1%. The organic product effectiveness of 0.2% concentration was found by observing reduction in the eggs mass compared to control group. The nanomaterial proved capable to anchor and release the acaricide gradually in pH between 6 and 7, which makes it feasible for use in cattle, prolonging the exposure time between the tick and acaricide.

Keywords: Cerrado specie, Rhipicephalus (Boophilus) microplustick, ectoparasites, tick control, acaricide, chitosan nanoparticle