Potencial uso da manipueira no controle larvicida do Aedes aegypti

Abstract

For the elimination of Aedes aegypti mosquito, vector of diseases such as dengue fever, yellow fever, zika virus and chikungunya fever, some control methods are used as the mechanical, chemical and biological. However, recent studies are being carried out with the aim of eliminating or controlling this vector with the lowest possible environmental impact. Cassava wasterwater is a light-yellow milky liquid that drips from the roots of the manioc. It is considered as a suspension due to the presence of small solid particles of starch in the liquid. The toxicity of the manipueira is consequent of the β-glucoside linamarina that is easily hydrolyzed in hydrocyanic acid. Environmentally, it is a problematic waste because it has a high pollutant load with toxic effect. Improper accommodation or disposal in the environment causes negative effects on the soil, humans and animals and renders aquatic life impossible. But because of its diverse chemical composition, it has been the subject of several studies, such as its use as fertilizer, biogas, herbicide, insecticide, nematicide and larvicide. The objective of this work was to investigate the larvicidal potential of the fractionated manipueira in crude, centrifuged and lyophilized residues. The larvicidal activity against Ae. aegypti was evaluated at the concentrations of 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90 and 100 mg L-1. The results showed that the concentration of manipulative influence on the efficiency of the larvicidal activity and that both the raw residue and the centrifuged residue exhibit a potential larvicida against Ae. aegypti, obtaining 100% larval mortality at concentrations of 70 mg L-1 in both fractions, however, the centrifuged residue is even more efficient, since the mortality was also effective at lower concentrations, noticeable in the LC50 value found that was 36.78 mg L-1 for the crude residue and 23.17 mg L-1 for the residue centrifuged. The lyophilized residue test did not present larvicidal activity, as it did not observe any mortality of Ae. aegypti in 24 hours of assay.