Abstract

To eradicate insects chemical insecticides have been used for long time. Synthetic insecticides have created havoc in the environment by altering the environment as well proved toxic no non-target animals/organisms. Hence, the focus to control the insects is now shifted to naturally occurring plant based insecticides which are eco-friendly. Among the insects, mosquitoes form important vectors as they transmit diseases like malaria and lymphatic filariasis etc. The present study is carried out to investigate the larvicidal activity of four different plants against Culex quinquefasciatus (vector of lymphatic filariasis) and Anopheles stephensi (malaria). There are many studies which state that the plant crude extracts act against mosquito as larvicidal, pupicidal, and adulticidal agents. As plants have antioxidant, toxic and bioactive properties they are used extensively in mosquito control. The chosen plants in this study are Ipomoea carnea (Leaves), Commiphora caudate (Leaves), Euphorbia ant quorum (Latex) and Acapulco senna-alata (Leaves). Ethanol, Methanol and Acetone extracts from four plants were tested against late third instar larvae of Culex quinquefasciatus and Anopheles stephensi. The larvae were exposed to different concentrations of plant crude extracts. After 24 hours the mortality rate of each dose was observed. There was no mortality in control. Among the plants screened, Ipomoea carnea (Leaves), crude extract showed highest mortality (100%), followed by Commiphora caudate (Leaves) which is 97%. The other two plants such as Euphorbia antiquorum and Acalpulco senna-alata showed 86% and 78% mortality respectively. The chemical composition of plant crude extract were analyzed by GC-MS and given herewith. The plant extracts needs to be tested for further as an effective larvicidal under field conditions.