在室内恒温条件下 ,采用乙醚半麻醉点滴法测定了异丙威、噻嗪酮及其复配对稻褐飞虱 4龄若虫的毒力 ,用Horsfall的毒力试验设计和Sun的共毒系数法评价了 2种药剂的联合作用。结果表明 ,异丙威与噻嗪酮混用 ,其LC5 0 剂量异丙威与噻嗪酮比例 ,除 6∶4和 1∶1两个配比外 ,其余配比均有显著的增效作用。其中以LC5 0 剂量 1∶9配比增效作用最大 ,毒性比率达 2 .0 8,共毒系数达 2 46 .86。 The toxicity of isoprocarb, buprofezin and their combination to the 4th instar nymphs of the brown planthopper, Nilaparvata lugens, was determined by semi-aether instillation at room temperature under laboratory conditions. The toxicity was evaluated using Horsfall’s virulence design and Sun’s co-toxicity coefficient 2 kinds of agents combined effect. The results showed that the combination of isoprocarb and buprofezin, its LC50 dose of isoprenoid and buprofezin ratio, in addition to the 6: 4 and 1: 1 two ratio, the rest of the ratio have significant synergies. In which LC5 0 dose ratio of 1: 9 the largest synergistic effect, the toxicity ratio of 2.08, co-toxicity coefficient of 246.68.