Larvicidal activity of essential oil from citrus sinensis and Citrus paradisi against Anopheles gambiae

Malaria is a major health challenge in the developing world causing millions of death annually. Synthetic pesticides used in the vectors control are not environmentally safe and are expensive. We screened the essential oils of Citrus sinensis and Citrus paradisi peels at concentrations ranging between 40 and 400 ppm against late 3rd instar of Anopheles gambiae larvae. The effects of ethanol and methanol on the larvicidal activity of these oils were examined. The effects of combined oils formulations on larvicidal activity were also determined. The larvicidal concentration (LC50) of the orange and grape oil was 73ppm and 76 ppm, respectively in methanol, and 121 ppm and 82 ppm in ethanol solution. The LC50 of the combined oil formulations ranged between 54 and 99ppm. The different oil combinations showed synergism except when combined at equal proportion in ethanol. Conclusively, orange and grape oils could be used as biopesticides against A. gambiae larvae.Keywords: Anopheles gambiae; Citrus paradisi; Citrus sinensis; essential oils; Mosquito larvaeBiokemistri 28(1): 16–2