Repellent Activities of Ethanolic Extract of Cymbopogon citratus (Poaceae) and Ocimum basilicum L. (Lamiaceae) Leaves in Malaria Vector Control in Dogbo District in South-Western Benin, West Africa

The use of chemical insecticides causes important damages to environment and human health and there is a need to search for alternative solutions. The current study was aimed to evaluate the repellent activities of ethanolic extract of Cymbopogon citratus (Poaceae) and Ocimum basilicum L. (Lamiaceae) leaves against Anopheles gambiae s.l female adult mosquitoes in malaria vector control in Dogbo district in south-western Republic of Benin. Larvae of Anopheles gambiae s.l mosquitoes were collected from breeding sites using the dipping method from September to November 2023 during the small rainy season in Dogbo district of Couffo department. Then, these larvae were reared in insectary until became adult mosquitoes. Repellent activities of ethanolic extract of both tree leaves were measured on female adult mosquitoes of four instars with different concentrations of 1mg/cm2, 2mg/cm2, 3mg/cm2, 4mg/cm2 and 5mg/cm2. The results showed that the leaves of both trees had repellent effects against Anopheles gambiae sensu lato female adult mosquitoes. However, the repellent activity of Cymbopogon citratus was higher than that of Ocimum basilicum L. Both ethanolic extracts of Cymbopogon citratus and Ocimum basilicum L. leaves are found to be effective in the repellency against the bites of Anopheles gambiae sensu lato female adult mosquitoes.