Chemical Constituents of The Essential Oils From The Leaves of Litsea umbellata and Litsea iteodaphne and Their Mosquito Larvicidal Activity

The chemical constituents of hydrodistilled essential oils from the leaves of Litsea umbellata (Lour.) Merr. and Litsea iteodaphne (Ness) Hook. f. growing wild in central Vietnam and mosquito larvicidal activity of these oils against laboratory-reared larvae of Culex quinquefasciatus and Aedes albopictus were in- vestigated. The major constituents mostly terpenes (percentage abundance, respectively) of the oils were beta- pinene (18.8 % and 6.6 %), beta-caryophyllene (16.2 % and 21.4 %), alpha-pinene (10.4 % and 8.7 %) and germacrene D (9.1 % and 15.5 %). The oil of L. umbellata displayed larvicidal activity against Cx. quinquefasciatus with LC50 of 36.19 mu g/mL at both 24 h and 48 h, while LC50 of 40.09 mu g/mL and 27.33 mu g/mL at 24 h and 48 h respecti- vely, were exhibited towards Ae. albopictus. Also, an LC90 value of 54.17 mu g/mL was obtained against Cx. quinquefasciatus at both 24 h and 48 h, while values of 68.79 and 60.49 mu g/mL respectively, were recorded against Ae. albopictus at 24 h and 48 h. Moreover, the oil of L. iteodaphne exhibited activity against Cx. quinquefasciatus with LC50 of 37.20 mu g/mL (24 h) and 20.21 mu g/mL (48 h) while LC90 values were 39.27 mu g/mL (24 h) and 23.78 mu g/mL (48 h). Furthermore, L. iteodaphne oil displayed larvicidal activity against Ae. Albopictus with LC50 values of 40.04 mu g/mL (24 h) and 16.63 mu g/mL (48 h) as well as LC90 values of 42.40 mu g/mL (24 h) and 23.64 mu g/mL (48 h). This is the first report on the chemical composition and larvicidal activity of L. umbellata and L. iteodaphne essential oils.