喜树碱对稻飞虱、二化螟和蚜虫的杀虫作用评价

Insecticidal Effect of Camptothecin against Nilaparvata Lugens,Brevicoryne Brassicae and Chilosuppressalis Walker

以喜树碱为活性成份，筛选新生物源杀虫剂。室内生物测定结果表明：0．2％的喜树碱乳油对甘蓝蚜虫、水稻稻飞虱和二化螟有较高的生物活性，其蛾和LC90分别为0．1～0．6mg／L和0．4～5．0mg／L，其对3种靶标害虫的活性大小依次为：水稻稻飞虱〉甘蓝蚜虫〉水稻二化螟。田间试验发现，0．2％的喜树碱乳油对蚜虫和稻飞虱的最大防效达到70％～95％，对照药剂10％蚜虱净的最大防效为63％-98％，两者无显著差异；0．2％的喜树碱乳油对水稻二化螟的保苗效果和防效分别为85％和88％，同时5％锐劲特的保苗效果和防效分别为93％和95％两者无显著差异。因此，喜树碱是具有较高活性的新生物源杀虫剂。

The insecticidal effect of camptothecin against Nilaparvata Lugens, Brevicoryne Brassicae and Chilosuppressalis Walker was carded out under laboratory and field tests. A bioassay showed that 0.2% camptothecin has strong contact toxicity, with LC50 and LC90 values of 0.1 - 0.6 mg· L^- 1 and 0.4 - 5.0 mg· L^- 1 respectively. The descending order of activity was： Nilaparvata lugens 〉 Brevicoryne brassicae 〉 Chilo suppressalis. Field tests showed that the survival rate of B. brassicae and N. lugens were between 70% and 95 %, which were not significantly different from the 10% imidacloprid WP control values of 63 % and 98 %. The survival and susceptibility of C. suppressalis were 85 % and 88 %, respectively, which were not significantly different from the 5 % Regent SC control values of 93 % and 95 %, respectively. The results showed that camptothecin has strong insecticidal activity against above three agricultural pests.