Biological activity of dried leaves from Neem tree, Azadirachta indica, on the Aedes aegypti larvae

Abstract

This paper aimed to produce experimental evidences on the possibility of the use the dried leaf of the neem tree, Azadirachta indica, aqueous extract as a natural insecticide to Aedes aegypti, the vector of Dengue. It is justified by the fact that the available wide range insecticides exterminate indiscriminately dangerous as well as useful insects to mankind. Another problem of wide range insecticides is the growing resistance shown by insects to them, what had been leading to the demands of higher concentrations at each application. The larval mortality of A. aegypti at the 3rd and 4th stages exposed to extract concentrations of 0.4% and 0.8% suggest a consistent perspective for its use as insecticide, when compared to the mortality of non-treated ones. The bioassay had shown wide possibilities to the use of dried leaves extract of neem tree as a natural insecticide to control dengue. In inspite of that, some other trials should be done to consolidate the methodology of water instead of organic solvent extraction of dried leaves of A. indica in the natural control of A. aegypti.