Knockdown effect of crude ethanol extracts of <i>Phytolacca dodecandra</i> on <i>Anopheles gambiae</i> adults

Abstract

Introduction: This study reports on knockdown effect of ethanol extracts of leaf and mature green fruits of Endod ( Phytolacca dodecandra ) against laboratory and wild laboratory reared Anopheles gambiae mosquitoes. Materials and Methods : Three modeled surfaces of the size 26 x 26 cm 2 cut from plywood were used. The first was smeared with a mixture of mud and cow dung, the second was smeared with cement and the third left as it was (plain or unsmeared). The surfaces were sprayed with an approximate of 33 mls of different concentrations (80, 40, 20, 10, 5, 2.5mls) of ethanol extracts of mature green fruits and leaves of Endod, leaves of Neem and deltamethrin. Rain water alone was used as control. Three to five day old unfed female An. gambiae were exposed for five minutes to the treated surfaces, withdrawn, placed in paper cups and observed for knockdown and recovery. Results: The highest number of knockdown for the test extracts was observed for Endod leaf extracts on cement and plain modeled surfaces (100%) against wild lab reared mosquitoes and mature green fruits on modeled plain surfaces (71%) for against lab reared mosquitoes. Extracts of Neem knocked down the highest number of wild lab reared mosquitoes (90%) on mud smeared surfaces. Deltamethrin knocked down all while rain water knocked down none of exposed mosquitoes. Conclusion: Ethanol extracts of Endod knocked down An. gambiae mosquitoes rapid enough showing great potential as a future malaria vector control tool. Further purification and tests are however recommended.