Larvicidal efficacy of the Citrus limetta peel extracts against Indian strains of Anopheles stephensi Liston and Aedes aegypti L.

The extracts from the peels of Citrus limetta were prepared using hexane and petroleum ether as the solvents. The larvicidal potential of each extract was assessed against dengue fever vector, Aedes aegypti, and malarial vector, Anopheles stephensi, by evaluating the toxicity effects on early fourth instars. Both the extracts were found effective against both the species. The bioassay with hexane extracts resulted in LC(50) values of 132.45 and 96.15 ppm against A. stephensi and A. aegypti, respectively; while the petroleum ether extracts from the C. limetta peels showed LC(50) values of 244.59 and 145.50 ppm, respectively. It revealed that the hexane extracts possessed 1.9-fold more larvicidal potential against A. stephensi and 1.5-fold more efficacy against A. aegypti as compared to the extracts obtained using petroleum ether as solvent. The data further revealed that the extracts were 1.4-1.7 times more effective against A. aegypti as compared to A. stephensi. The qualitative phytochemical study of the extracts showed the presence of terpenoids and flavonoids as the common phytochemical constituents in the extracts suggesting their possible role in the toxicity. Other constituents tested were not detected except alkaloids which were found to be present only in the petroleum ether extract. Further studies are needed to isolate and identify the active principles involved, their mode of action, formulated preparations for enhancing potency and stability, toxicity, and effects on non-target organisms and the environment. This could help in formulating efficient strategies for mosquito control.