四种植物精油对黑翅土白蚁触杀和驱避作用

为筛选出高效防治黑翅土白蚁的天然植物精油,减少有机合成农药的使用,该文研究了大蒜精油、肉桂油、丁香油和印楝素油四种植物精油对黑翅土白蚁的触杀效果和驱避作用。结果表明:大蒜精油、肉桂油和丁香油的浓度为5和10 mg·m L~(-1)时,处理2 h后,黑翅土白蚁的校正死亡率达100%,而相同浓度的印楝素油和对照处理的黑翅土白蚁校正死亡率低于5%。随着处理时间延长,浓度为1.25和2.5 mg·m L~(-1)的大蒜精油、肉桂油和丁香油处理6 h时,黑翅土白蚁的校正死亡率仍达100%,而此时对应的印楝素油和对照处理的黑翅土白蚁校正死亡率仅为10%,说明大蒜精油、肉桂油和丁香油对黑翅土白蚁具有较强的触杀效果。大蒜精油、丁香油和肉桂油在处理黑翅土白蚁2 h后LC_(50)值(半致死量)分别为1.572、1.05和1.03mg·m L~(-1),说明肉桂油对黑翅土白蚁的毒性相对最大,触杀效果最好。此外,10 mg·m L~(-1)的大蒜精油、肉桂油、丁香油和印楝素油的驱避试验表明,处理4、6、8和12 h后,大蒜精油、肉桂油和丁香油三精油处理区的黑翅土白蚁数均显著低于对照区的,驱避率总体93%,而对应的印楝素油的驱避率总体28.5%,表明大蒜精油、丁香油和肉桂油三种植物精油对黑翅土白蚁均有显著的驱避活性。综上可知,四种植物精油中大蒜精油、肉桂油和丁香油在防治黑翅土白蚁方面应用潜力很好,是开发绿色环保白蚁防治药剂的可选材料。

Contact toxicity and repellency of four plant oils against Odontotermes formosanus

In order to study some natural plant oils with effective prevention of Odontotermes formosanus and reduce the use of synthetic organic pesticides, contact toxicity and repellency of four plant oils against O. formosanus were studied, including garlic essential oil, cinnamon oil, clove oil and neem oil. The results indicated that the corrected mortality of O. formosanus was 100% in the treatments with 5 and 10 mg·mL^-1 of garlic essential oil, cinnamon oil and clove oil after 2 h. However, the corrected mortality of O. formosanus was less than 5% in the treatments with 5 and 10 mg·mL^-1 of neem oil and control after 2 h. With the extension of treatment time, the corrected mortality of O. formosanus was also 100% in the treatments with 1.25 and 2.5 mg·mL^-1 of garlic essential oil, cinnamon oil and clove oil after 6 h, but the corrected mortality of O. formosanus was only 10% in the treatments with 1.25 and 2.5 mg·mL^-1 of neem oil and control after 6 h. The above results showed that garlic essential oil, cinnamon oil and clove oil had strong effects on the contact resistance to O. formosanus. Therefore, the lethal concentration 50(LC₅₀ values)of garlic essential oil, clove oil and cinnamon oil to O. formosanus were 1.572, 1.05 and 1.03 mg·mL^-1 respectively after 2 h, suggesting that cinnamon oil had the biggest contact toxicity against O. formosanus. Additionally, the repellent experiments showed that the number of O. formosanus in the treatment area with 10 mg·mL^-1 garlic essential oil, cinnamon oil or clove oil was significantly lower than that in the control area after 4, 6, 8 and 12 h, and the repellent efficiencies were all higher than 93%, while the repellent efficiency of neem oil was all less than 28.5%, which indicated that garlic essential oil, cinnamon oil and clove oil had significant repellent effect on O. formosanus in four selected plant oils. The above results showed that garlic essential oil, cinnamon oil and clove oil had good application prospects in the prevention and control of O. formosanus, and such three essential oils were optional materials to the development of green environmental protection and control of O. formosanus.