Evaluation of the Larvicidal Potential of the Leaf Extracts of Hyptis suaveolens Poit against Anopheles Mosquitoes

This study evaluated the larvicidal potential of the ethanolic and aqueous leaf extracts of Hyptis suaveolens Poit on the 4th larval instar of laboratory-reared Anopheles 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 phytochemical screening of the leaf extracts identified bioactive components like alkaloid, saponin, phenol, anthraquinone and flavonoid. The LC50 and LC90 values obtained indicate that the ethanolic leaf extracts of Hyptis suaveolens Poit had the greatest toxicity on the test organisms within 24hrs of exposure at median LC50 value of 0.485ml compared to the LC50 value of 0.625ml by its aqueous extract. The relative median potency estimates indicate that within 24 hrs, the ethanolic Hyptis suaveolens Poit was 0.161 times more potent on the test organism than aqueous Hyptis suaveolens Poit. The result of this research, therefore, underscores the efficacy of Hyptis suaveolens Poit as an eco-friendly alternative in Anopheles 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 isolate and purify toxic phytochemicals with larvicidal potentiality.