Mini-review on the efficacy of aquatic macrophytes as mosquito larvicide

Abstract

Malaria is a mosquito-borne disease, which is endemic in Asia, Africa and Latin America. Vector control is the current strategy used for the eradication and elimination of malaria in these countries, but this control method has not proven to be effective, as malaria continues its increasing trend. Although chemical larvicide can also be used to eradicate the malaria vector at the larval stage, preventing the growth of mosquitoes into hematophagous adults, the continuous use of chemical insecticides leads to environmental pollution. It is therefore of paramount importance to identify effective, low-cost, biodegradable and environmentally friendly alternatives to chemical insecticides for the control of mosquito larvae. This mini-review aims to assess the present and future of the use of macrophytes as a mosquito larvicide. We critically analyze the trend of malaria cases in sub-Saharan Africa and evaluate why botanical larvicides may contribute to the eradication of malaria in the region. The ecological role of macrophytes in the aquatic environment and their potential as botanical larvicide are explained in detail. The study illustrates that the macrophytes Azolla pinnata, Pistia stratiotes, Eicchornia crassipes, Phragmites australis, Nelumbo nucifera, Nymphaea lotus, Typha latifolia and Leucas martinicensis have been effectively used as larvicides against mosquito larvae. It is recommended that additional work be done to purify the biologically active components that are responsible for the larvicidal activity of these macrophytes, and future research should assess the potential of other macrophytes for effective utilization as larvicides.