中文摘要：

用一个采自武汉地区的甜菜夜蛾田间种群（N）和一个相对敏感种群（CK），比较了甜菜夜蛾的表皮酚氧化酶（PPO）、乙酰胆碱酯酶（TCE）、谷胱甘肽S转移酶（GST）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）酶活力差异。用含有0．14mg／kg（致死中量）虫酰肼的带毒饲料处理CK种群的甜菜夜蛾，处理后24、48h和72h测定酶活力，结果与CK种群相比，PPO酶活力分别降低79．12％、10．54％和56．23％；SOD酶活力分别上升71．59％、63．16％和79．55％；GST酶活力在处理后24h酶活力上升41．43％。N种群与CK种群比，PPO酶活力降低38．47％；GST酶活力升高34．20％。采用PAGE凝胶电泳方法比较了CK、N和用虫酰肼分别汰选CK种群4代和6代的甜菜夜蛾种群酯酶同工酶谱差异。结果表明，CK共有15条酯酶同工酶带，N和汰选种群均只有10条带。研究结果初步表明甜菜夜蛾对虫酰肼的抗药性可能与PPO、GST、SOD、EI酶活力变化有关，与CAT关系不大，与TCE无关。

英文摘要：

Activities of polyphenoloxidase （PPO）, true choline esterase （TCE）, glutathione-S-transferase （GST）, superoxide dismutase （SOD） and catalase （CAT） of the beet armyworm, Spodoptera exigua （Hfibner）, were tested in vivo in a relatively susceptible population （CK） kept in the laboratory and a population （N） collected from vegetable field in Wuhan. The CK population was treated with 0.14 mg/kg（LC50） tebufenozide. At 24 h, 48 h and 72 h after treatment, the activities of PPO decreased by 79.12%, 10.54% and 56.23%, respectively. And SOD activities increased by 71.59%, 63.16% and 79.55%, respectively. The GST activities increased by 41.43% after 24 h treatment. Compared with the CK population, PPO activity of the N population decreased by 38.47% and GST activity increased by 34.20%. Using PAGE method, the esterase isoenzymes in CK population, N population and the tebufenozide-selected populations of four and six times, were determined. The results indicated that there were 15 isozyme bands in CK population, but 10 bands in N and the two selected populations. Preliminary results showed that tebufenozide resistance in the beet armyworm might be related to the PPO, GST, SOD and EI, but not to the CAT and TCE.