Bioactivity Evaluation of Mangifera indica (Mango) Leaves Ethanolic Extract on 3rd -Early 4th Instar Aedes aegpyti Larvae

Abstract

Aedes aegyptiis the main vector of dengue, which causes morbidity. In response to this, various low cost and easy to prepare plant-based larvicides have been developed. In this study, Mangifera indica(Mango) leaves were evaluated for its bioactivity on 3rd–early 4thinstar Aedes aegypti larvae. Sundried and ground mango leaves were macerated in 95% ethanol and purified using rotary evaporation. The ethanolic extract was serially diluted into different concentrations: 10,000 ppm, 15000 ppm, 20,000ppm, 25,000ppm, 30,000ppm, 50 ml crude extract and distilled water as negative control. Ovicidal/Larvicidal traps were used to collect Aedes aegyptieggs and continuously reared in black plastic cups. The mortality of the larvae was recorded and evaluated for its actual morphology during and after exposure to the extract. One-way ANOVA result showed a significant difference among the treatments in terms ofthe mortality rate [F = 3.101, p = 0.027] wherein the crude treatment obtained the highest average mortality rate. This testified that M. Indica leaves extract was dose-dependent with lethal concentration to kill 50% and 90% of the larvae at30511.612 ppm and 86963.689 ppm respectively. The morphology of Aedes aegypti larvae affirmed serious aberration on the mid-gut and proventriculus. There was also the peculiar preservation of the larvae’s body observed after eight days due to the constituent tannin-an astringent that caused the tissues to contract. Therefore, M. indica leaves ethanolic extract could be a potential bio-larvicide, which can be utilised to control Aedes aegypti which is the primary vector of the dengue virus.