香桂（ Cinnamomum subaνenium Miq. ）葉子精油組成分相當多樣，本研究分析3株 香枝葉子精油成分，並評估3株香桂葉子精油抑制埃及斑紋（ Aedes aegypti） 和白線斑妓 (A. albopictus ）二種幼蟲的致死功效。結采顯示3株香桂葉子精油皆』:J.p-Cyrnene （對異丙基甲笨）為主要成分，香桂A和香桂B 葉子精油之次要成分為Linalool 、1,8Cineole及 Caryophyllene oxide:香桂C 葉子精油之次要成分為α-Phellandrene 、Eugenoi及 Caryophyllene oxide 。另外，亦評估3株香桂葉子精油及其主成分抗病媒妓幼蟲活性，其中，以香桂C葉子精油之效采最佳， 試驗24hr後，對埃及斑紋及白線斑紋幼蟲之半數致死 濃度分別為190.5μg/mL 及169 .3 μg/mL ，而主要活性成分則是p-Cymene 及α-Phellandrene ，兩者對埃及斑紋和白線成蚊幼蟲之半數致死濃度分別為62. 0 μg/mL和67 .7 μ g/mL及97.4 μg/mL和65.4 μg/mL。綜合試驗結呆顯示，香桂C葉子精油本身以及精油成分p-Cymene手。α-Phellandrene均很有潛力成為做為天然的殺蚊子幼蟲欒劑。

Components of leaf essential oils from Fragrant Cinnamon (Cinnamomum subavenium Miq.) are var iable. This paper evaluated the chemical compositions and the mosquito larvicidal mortality activity of three leaf essential oi ls from C. subavenium (trees A, B and C) against two mosquito species, Aedes aegypti and A. albopictus. Results showed that the major compound is p-cymene in all three C. subavenium geographical provenances, minor compounds are linalool, 1,8-cineole and caryophyllene oxide in trees A and B and a -phellandrene, eugenol and caryophyllene oxide in tree C. Meanwhile, the anti-mosquito 4th instar larva abilities of these 3 essential oils and their major components were investigated. C. subavenium leaf essential oil (Tree C) has the best activity among the 3 essential oils, its median lethal concentration (LCso) value against A. aegypti and A. albopictus 4th instar larvae after 24 hr were 190.5 μ g/mL and 169 .3 f.1 g/mL, respectively. On the other hand, it also showed that the effective constituent in leaf essential oil were p-cymene and a -phellandrene, their LCso values against A. aegypti and A. albopictus 4th instar larvae after 24 hr were 62.0 μ g/mL, 67 .7 μ g/mL and 97 .4 μ g/mL, 65.4 f.1 g/mL, respectively. These results clearly showed that C. subavenium leaf essential oil (Tree C) and p-cymene, a -phellandrene are of great potential to be used as natural insecticidal agents for mosquito control.