Natural Product Pesticides: Their Development, Delivery and Use Against Insect Vectors

Natural chemicals have considerable potential for vector management because these chemicals are safer than conventional insecticides on account of their rapid environmental biodegradation and low toxicity to natural enemies, humans and other mammals and they suffer less from problems of registration difficulties. However, isolation and chemical characterization of the active compounds from plants with strong biological activities can be a tedious process compared to synthesizing new synthetic compounds because natural compounds are generally isolated in small amounts. In addition, the purity of natural products is highly variable and is dependent upon the extraction method, plant part, plant age, geographic origin and location, climate and the overall growth and health of the plant from which the chemical is extracted. Furthermore, the research and development of natural pesticides against insect vectors is constrained because of the perceived lack of economic return to the manufacturers on investment in insect vector control and also due to the difficulties in registration. Despite these difficulties, research in plant-derived pesticides has increased considerablly. In this paper we provide an overview of the compounds isolated from plants that have been evaluated for control of insect vectors of human and animal pathogens.