Comparative Larvicidal Potential of the Leaf Extracts of Hyptis suaveolens Poit against Anopheles and Culex Mosquitoes

This study evaluated the larvicidal potential of the ethanolic and aqueous leaf extract of Hyptis suaveolens Poit on the 4^th larval instar of laboratory-reared Anopheles spp and Culex spp at varying concentrations of 0.1ml, 0.2ml, 0.3ml, 0.4ml and 0.5ml for specified periods of 24hrs, 48hrs and 72hrs. Qualitative phytochemcial screening of the leaf extract identified bioactive components like alkaloid, saponin, phenol, anthraquinone and flavonoid. The LC₅₀ and LC₉₀ values obtained from Probit Analysis using SPSS version 20 at 95% confidence limit (CL) (P≤0.05) indicate that the ethanolic leaf extracts of Hyptis spp had the greatest toxicity on Anopheles spp and Culex spp within 24hrs of exposure at median LC₅₀ values of 0.485ml and 0.497ml respectively. Ethanolic Hyptis spp was 0.061 times more potent on Anopheles spp than Culex spp. The results of this research, therefore, underscores the efficacy of the plants especially Hyptis suaveolens Poit as an eco-friendly alternative in mosquito control. It is, therefore, recommended that quantitative phytochemical screening, application of column chromatography as well as thin layer chromatography be carried out on the extracts to purify and isolate toxic phytochemical with larvicidal potentiality.