三种植物精油对致倦库蚊成蚊的熏蒸活性及其混配增效作用

研究了香樟叶、香樟果实、天竺桂叶的水蒸气蒸馏精油对致倦库蚊Culex pipiens quinquefasciatus成蚊的熏蒸活性及其混配增效作用。结果表明:用香樟叶、香樟果实和天竺桂叶精油对致倦库蚊熏蒸20 min后,其24 h的LC50值分别为7.47、4.92和5.70μg/cm3;在设定的熏蒸剂量下,3种精油的半数击倒时间(KT50值)分别为16.62、15.91和16.98 min。将香樟叶精油与天竺桂叶精油以体积比1∶9、3∶7和5∶5混配,其共毒系数分别为152.09、158.20和152.86;将香樟果实精油与天竺桂叶精油以体积比1∶9、5∶5和7:3混配,其共毒系数分别为145.73、146.30和139.79。表明3种植物精油均对致倦库蚊成蚊具有显著的熏蒸活性,将其以适当比例混配后具有增效作用。

Fumigation activity of three plant essential oils against Culex pipiens quinquefasciatus and synergistic effects of their mixtures

The fumigation activity and synergistic effects of certain mixtures of steam-distilled essential oils from Cinnamomum camphora leaves, Cinnamomum camphora fruits and Cinnamomum pedunculatum leaves against Culex pipiens quinquefasciatus was evaluated. The results showed that the fumigation 24 h LC50 values of essential oil from C. camphora leaves, C. camphora fruits and C. pedunculatum leaves against adults of C. pipiens quinquefasciatus were 7.47, 4.92 and 5.70 μg/cm3, respectively. At the given dosage of fumigation, the KT50 values (the time to knock down 50% of the mosquito population) were 16.62, 15.91 and 16.98 min, respectively, when the fumigation time was 20 min. The co-toxicity coefficient of C. camphora leaves oil and C. pedunculatum leaves oil mixed at a volume ratio of 1:9, 3:7 and 5:5 against mosquito adults were 152.09, 158.20 and 152.86, respectively. The co-toxicity coefficient of C. camphora fruits oil and C. pedunculatum leaves oil mixed at a volume ratio of 1:9, 5:5 and 7:3 against mosquito adults were 145.73, 146.30 and 139.79, respectively. The results showed that the three essential oils possessed high fumigation activity against C. pipiens quinquefasciatus, and the certain ratio mixtures of the oils revealed remarkable synergistic effect of fumigation against C. pipiens quinquefasciatus.