Management of Oviposition Attractant and Symbiotic Bacterial Flora of the Malarial Vector Anopheles subpictus (Grassi, 1899) by Plant Extracts

Abstract

Anopheles subpictus is one of the potent vectors of malarial diseases in different parts of the world. The present study is destined to control the bacterial strains which act as oviposition attractant as well as successful development of this vector species in its environment by an eco-friendly approach. Antibacterial efficacy of crude extracts of different plants were tested against eight bacterial isolates. Solvent extracts were prepared and antibacterial efficacy with MIC value was tested. Effect of most active solvent extract fraction on An. subpictus mosquito was determined. Among twenty-five different plant leaves extract tested, Xanthium strumarium gave highest antibacterial activity against all the tested bacterial isolates. Among different solvent extract fraction petroleum ether fraction gave highest ZDI value against all the tested bacterial isolates. Scanning electron microscopic analysis revealed several morphological deformities in bacteria. Application of active solvent fraction also reduced successful emergence of adult mosquitoes from eggs to a great extent. This study suggested that isolation and formulation of bio-active compounds from petroleum ether fraction of X. strumarium leaves will provide an alternative eco-friendly source of chemical insecticides to control malarial vector populations in Hooghly district.