Repellent activities of ethanolic extract of Hyptis suaveolens Linn (Lamiaceae) and Azadirachta indica (Meliaceae) leaves against Aedes aegypti mosquitoes in Lokossa 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 Hyptis suaveolens Linn and Azadirachta indica leaves against Aedes aegypti adult mosquitoes in dengue vector control in Lokossa district in south-western Republic of Benin. Larvae of Aedes aegypti mosquitoes were collected from breeding sites using the dipping method from March to July 2024 during the great rainy season in Lokossa district of Mono department. Then, these larvae were reared in insectary until became adult mosquitoes. Repellent activities of ethanolic extract of both plant leaves were measured on adult mosquitoes 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 Aedes aegypti adult mosquitoes. However, the repellent effect of Azadirachta indica leaves was higher than that of Hyptis suaveolens Linn leaves. Both ethanolic extracts of Hyptis suaveolens Linn and Azadirachta indica leaves are found to be effective in the repellency against the bites of Aedes aegypti adult mosquitoes.