Ovicidal, larvicidal and adulticidal activity of Citrus grandis L. (Osbeck) against dengue vector, Aedes aegypti (L.)

Abstract

Recent studies regarding the harmful effects of synthetic larvicides initiated the need to investigate for unconventional measures that are environmentally-safe and target-specific against Aedes aegypti larvae. Thus, the main objectives of the study are to evaluate the ovicidal, larvicidal and adulticidal toxicity of the hexane extract of Citrus grandis peels against dengue vector, A. aegypti. Results revealed that the hexane extract of C. grandis peel from Davao exhibited the highest lethal concentration against 3^rd and 4^th instars larvae with an LC₅₀ and LC₉₀ of 1.11 mg/L and 3.32 mg/L, respectively. Moreover, the knockdown effect of the hexane extract of C. grandis peels on adult female A. aegypti produced 50% knockdown within 11.50 minutes and 90% knockdown within 28.79 minutes. The test mosquitoes’ mortality was 100% after 24 hours. Lastly, the ovicidal activity of the hexane extract against the eggs of A. aegypti exhibited an LC₅₀ of 13.84 mg/L and LC₉₀ of 25.30 mg/L. The remarkable effects exhibited by C. grandis peels indicate its great potential to be a more sustainable and environmentally-safe plant-based control for the proliferation of the dengue vector, A. aegypti.