A comparative Study of the Toxicity of Caesalpinia Pulcherrima (Caballero) and Nerium Indicum (Adelfa) applied in Various Concentrations to Culex Sp. Larvae and Sitophilus Zeamays Adults

Abstract

Caesalpinia pulcherrima (Caballero) and Nerium indicum (Adelfa) leaf extracts in various concentrations were tested for toxicity against 20 mosquito larvae, Culex sp. And 20 corn weevils, Sitophilus zeamays, by the immersion and paper impregnation methods, respectively. Extraction was by Soxhlet procedure using ethanol solvent to obtain 12:43% from Caballero leaves and 23.13% from Adelfa leaves. Mortality counts substantiated by statistical analysis revealed the non-toxicity of both extracts to corn weevils. However, they were slightly toxic to mosquito larvae with the 10 mg/ml concentration of Caballero extract yielding the highest mortality of 41.46%. Statistical analysis revealed significant differences in extracts and concentration as well as an integration of both variables.