Exploitation of Plant Herbs in the Control of Disease Vectors: A Review

Abstract

Diseases transmitted by vectors have been plaguing man since time immemorial causing millions of deaths annually. The highest occurrence reportedly occurs in tropical and subtropical areas where malaria, the commonest vector-borne disease, is highest. The management of vector-borne diseases has been basically by controlling their vectors using synthetic insecticides: the pyrethroids, organophosphates, organochlorines: carbamates. Reports have shown that these insecticides pollute the environment, result in bio-magnification and affect non-target organisms mostly man thereby raising health concern. Also, there is development of insecticide resistance in the disease vectors, which may hamper the effective use of the insecticides. These negative effects associated with the use of synthetic insecticides emphasize the need for alternative method of control. The control of disease vectors with the use of herbal-based products that have insecticidal properties is promising as it is safe to non-target organisms, eco-friendly, bio-degradable, less expensive and the development of resistance in the vectors is more or less absent. The insecticidal activity of plant herbs is attributed to the presence of complex mixture of bio-active compounds, which act as anti-feedants, oviposition deterrents, repellents, attractants, etc. Using relevant literatures, this paper discussed disease vectors, method of transmission of vector-borne diseases, the need for alternative method of disease vector control and the most common plants employed in the control of disease vectors including their families, products, bio-active compounds, their activity and mode of action. Use of plant herbs and their products can therefore, serve as alternative method for vector control programme.