冬青油与肉桂油对淡色库蚊的生物活性

为进一步明确冬青油（wintergreen oil）与肉桂油（cinnamon oil）对蚊虫的生物活性， 本研究采用浸液法、 “Y”型嗅觉仪法和密闭三角瓶熏蒸法， 分别测定了两种精油对淡色库蚊Culex pipiens pallens幼虫的毒杀作用以及对成虫的驱避和熏杀活性。结果显示： 肉桂油和冬青油对淡色库蚊幼虫均具有较强的毒杀作用， 处理24 h的LC₅₀分别为71.87 mg/L和 102.83 mg/L。在0.5 μL的供试剂量下， 冬青油与肉桂油在20 min内对淡色库蚊的驱避率均在80%以上， 显示了较好的驱蚊活性。冬青油对淡色库蚊具有明显的熏蒸击倒作用， 12 μL/L浓度下的KT₅₀为3.97 min； 而肉桂油则具有较好的熏蒸致死活性， 熏蒸5 h的LC₅₀ 为0.31 μL/L。冬青油与肉桂油按1∶1体积比混配后对淡色库蚊表现出较好的击倒和致死效果。冬青油和肉桂油既对淡色库蚊幼虫具有较强的毒杀作用， 又对淡色库蚊雌成虫表现出较好的驱避和熏杀活性， 具有开发成为植物源蚊虫防控剂的潜力。

Biological activities of wintergreen oil and cinnamon oil against Culex pipiens pallens (Diptera: Culicidae)

In order to evaluate the biological activities of wintergreen oil and cinnamon oil against mosquitoes, repellent and fumigant activities of wintergreen oil and cinnamon oil against Culex pipiens pallens were investigated via immersion method, “Y”-tube olfactometer and fumigation, respectively. The results showed that cinnamon oil and wintergreen oil had high larvicidal activity against C. pipiens pallens larvae, with the LC₅₀ values (24 h) of 71.87 mg/L and 102.83 mg/L, respectively. Wintergreen oil and cinnamon oil exhibited good repellent activity against C. pipiens pallens adults (percent repellency>80%) at the dosage of 0.5 μL within 20 min. Wintergreen oil had excellent knockdown activity against C. pipiens pallens adults at the dose of 12 μL/L with the KT₅₀ value of 3.97 min, and cinnamon oil exhibited high fumigation activity against C. pipiens pallens adults with the LC₅₀ value of 0.31 μL/L after 5 h exposure. The mixture (1∶1, v∶v) of wintergreen oil and cinnamon oil performed both rapid knockdown and high lethal toxicity against C. pipiens pallens adults, suggesting that they have a synergistic effect. Wintergreen oil and cinnamon oil showed high larcicidal activity against C. pipiens pallens larvae and good repellent and fumigation activities against female C. pipiens pallens adults, suggesting that wintergreen oil and cinnamon oil could be exploited as potential botanical mosquito control agents.