A Study on Larvicidal Activity of Medicinal Plant Extracts against Aedesaegypti

Abstract

Mosquitoes are vectors harbouring infection and are responsible for transmission of various dreadful diseases, causing millions of deaths every year. Random use of chemical insecticides has resulted in the development of resistance, resulting in revivingvectorial capacity. Such chemicals have also given rise to many serious environmental issues. To prevent the spreading of mosquito borne diseases and to improve the quality of environment and public health, mosquito control is essential, that are feasible and at the same time effective. This has led to the search for biologically active compounds in plants, which are having several advantages over the chemical insecticides for controlling vector species. The present attempt is to assess the larvicidal ability of the methanol and aqueous leaf extracts of nine medicinal plants extracts against mosquito larvae,Aedesaegypti. Mortality percentages, statistical analysis for determining significant differences and LC₅₀ were calculated. Larvicidal activity was found to be increasing at varying concentration and retention time for every plants selected. Out of the 18 test samples (methanol and aqueous medicinal leaf extracts) Lantana camara offers promised as a potential biocontrol agent against A. aegypti particularly in its markedly larvicidal effect. It shows that Lantana camaramethanolic leaf extract is the most effective in terms of larvicidal activity (lowest LC₅₀ value of 148.466 ppm after 72 hours of incubation). Further studies on the isolation and identification of the active compounds involved and their mode of action and field trials are needed to recommend L. camara as an anti-mosquito product used to combat and protect from mosquitoes in a control program.