Mosquito larvicidal potential of medicinal plants

Abstract

Mosquitoes act as vectors for many life-threatening diseases like malaria, yellow fever, dengue fever, chikungunya, filariasis, encephalitis, West Nile virus infection, etc. Vector control is by far the most successful method for reducing the incidence of mosquito-borne diseases, but the emergence of widespread insecticide resistance and the potential environmental issues associated with some synthetic insecticides has indicated that additional approaches to control the proliferation of mosquito population would be an urgent priority research. Mosquitoes develop genetic resistance to synthetic insecticides and even to biopesticide such as Bacillus sphaericus. Also synthetic insecticides adversely affect the environment by contaminating air, water, and soil. There is an urgent need to find alternatives to the synthetic insecticides which are more potent and low cost. Plants are a rich source of alternative agents for control of mosquitoes, because they possess bioactive chemicals, which act against a limited number of species including specific target insects and are eco-friendly. Traditionally, plant-based products have been used in human communities for many centuries for managing insects. Several secondary metabolites present in plants serve as a defense mechanism against insect attacks. These bioactive chemicals may act as insecticides, antifeedants, molting hormones, oviposition deterrents, repellents, juvenile hormone mimics, growth inhibitors, antimolting hormones, as well as attractants. Plant-based pesticides are less toxic, and there is a delay in the development of resistance because of their new structure and easy biodegradability. In present article, the local and traditional uses of plants in mosquito control, current state of knowledge on phytochemical sources, and the mosquitocidal properties of secondary metabolites have been reviewed.