Larvicidal activity of essential oils from Brazilian Croton species against Aedes aegypti L.

Aedes aegypti is the major vector of dengue fever, an endemic disease in Brazil. In an effort to find effective and affordable ways of controlling this mosquito, the larvicidal activities of essential oils from Croton species widely found in northeastern Brazil were analyzed. The essential oils were extracted by steam distillation, and their chemical composition was determined by gas liquid-chromatography coupled with mass spectroscopy. The main components were methyleugenol and alpha-copaene for C. nepetaefolius (LC50 of 84 ppm); alpha-pinene and beta-pinene for C. argyrophyloides (LC50 of 102 ppm); and alpha-pinene, beta-phelandrene, and trans-caryophyllene for C. sonderianus (LC50 of 104 ppm). Croton zenhtneri exhibited higher larvicidal activity with LC50 of 28 ppm, and the main active constituent was identified as anethole, a phenylpropanoid compound.