(1. Research & Development Center of Biorational Pesticides, Northwest A&F University, Yangling, Shaanxi 712100, China; 2. Research Center of Biopesticide Engineering & Technology of Shaanxi Province, Yangling, Shaanxi 712100, China）
Abstract 【Aim】 This study aims to obtain essential oils with higher bioactivities so as to provide more valuable materials for mosquito prevention and control. 【Methods】 The fumigation activity of thirty-six essential oils against Culex pipiens pallens adults was evaluated by airtight fumigation in sealed conical flasks or hermetic round canisters. 【Results】 The results of fumigation assay in sealed flasks showed that 10 essential oils including Pinus massoniana leaf oil, Magnolia oil, red moor besom leaf oil, dai-dai leaf oil, Forsythia oil, Perilla leaf oil, Elsholtzia oil, tea tree oil, vetiver oil, and Angelica oil possessed high toxicity against C. pipiens pallens adults with low KT50 values (＜10 min) at 12 μL/L, and P. massoniana leaf oil exhibited the highest fumigation activity with the KT50 value of 3.40 min. The fumigation of red moor besom leaf oil and grapefruit oil caused higher mortality rates at 24 h after treatment, with the LC50 values of 0.95 and 1.11 μL/L, respectively. The results of fumigation assay in hermetic round canisters revealed that the KT50 value of P. massoniana leaf oil against C. pipiens pallens adults was 13.79 min at the concentration of 12 μL/L, and the mortality rate of C. pipiens pallens adults caused by red moor besom leaf oil at the concentration of 1.67 μL/L was 100%. 【Conclusion】 P. massoniana leaf oil and red moor besom leaf oil have strong fumigation activity against C. pipiens pallens adults, and both oils thus hold great potential to be developed as mosquito control agents.