Efeito de extratos etanólicos de Capsicum frutescens, Lippia sidoides e Annona crassiflora sobre Rhipicephalus (Boophilus) microplus

Abstract

Damages caused by ticks are common in tropical and subtropical livestock. The control of these parasites with chemical acaricides can promote damage to human and animal health, promote the selection of resistant parasites and contaminate the environment. The use of plant extracts may be promising alternative. This study aimed to evaluate the effect of ethanol extract of ripe fruits of Capsicum frutescens L (chili pepper), leaves of Lippia sidoides Cham (rosemary-pepper) and of Annona crassiflora Mart (pana) on Rhipicephalus microplus. The engorged females from cattle raised in Francisco Sá, North of Minas Gerais were weighed, cleaned and distributed in the treatments after screening about the viability, physical integrity and degree of ingurgitation. There has been the split in descending order of size, to obtain homogeneous weight. In groups compounded of 10 ticks was added the ethanol extract of each vegetable. The concentrations 25, 50, 75, 100 and 150 mg mL-1 were solubilized in dimethylsulfoxide (DMSO) at 1% v/v. For negative controls were used 1% DMSO v / v diluted in distilled water. And pure distilled water. Commercial product based on cypermethrin, chlorpyrifos and citronellal was used as positive control. There were four replicates per treatment. The extracts of the three plants, at all concentrations tested, significantly inhibited the ability of position of engorged females. For the extract C. frutescens in a concentration equal to or greater than 75mg/ mL-1, the increase of the mortality rate and the reduction of capacity of posture occurred in a similar way to the positive control, containing the commercial acaricide, and it was found efficacy acaricidal equal or superior to 91,8%. It was verified the acaricide effect for the extracts evaluated, however, toxicology studies and in vivo are needed to display them in a safe and efficient alternative control of this tick.