Chemical compositions of crassocephalum crepidioides essential oils and larvicidal activities against aedes aegypti, aedes albopictus, and culex quinquefasciatus

Abstract

The leaf, stem, and floral essential oils of Crassocephalum crepidioides growing wild in central Vietnam were obtained by hy-drodistillation and analyzed by gas chromatography-mass spectrometry. The major component in all 3 oils was myrcene (59.3%, 26.1%, and 43.3%, respectively). The 24-hour mosquito larvicidal activities of the oil of the aerial parts (stems and leaves) were determined against wild-caught Aedes albopictus (IC50 = 14.3 μg/mL), laboratory-reared Aedes aegypti (IC50 = 4.95 μg/mL), and wild-caught Culex quinquefasciatus (IC50 = 18.4 μg/mL). The high concentration of myrcene in the essential oil likely accounts for the mosquito larvicidal activity observed.