中文摘要：

为明确茚虫威对甜菜夜蛾幼虫的作用特点，采用浸叶法和点滴法测定了茚虫威对甜菜夜蛾3龄和4龄幼虫的毒力，及其羧酸酯酶活性的影响。结果表明：茚虫威对甜菜夜蛾3龄和4龄幼虫均有胃毒毒力和触杀毒力，且胃毒毒力高于触杀毒力。同时，茚虫威对4龄幼虫的胃毒毒力（LC50为2．69mg·L-1）稍高于其3龄幼虫（LC50为3．65mg·L-1）。茚虫威对不同龄期的甜菜夜蛾幼虫体内羧酸酯酶的影响均表现为先激活后抑制，且对4龄幼虫的影响更强烈。茚虫威不同剂量处理对4龄幼虫的化蛹率、蛹重、羽化率及子代幼虫成活率产生了明显影响，影响程度为LC50〉LC30〉LC10。

英文摘要：

In order to determine the mechanisms of indoxcarb to the larvae of Spodoptera exigua （Htthner）, the toxicity of indoxcarb to 3rd - instar and 4th - instar larvae of the S. exigua was studied by dipping method and topical application method, and the impacts of indoxcarb on the activity of carboxylesterase in 3th - instar larvae of S. exigua were determined. Indoxcarb showed stomach toxicity and contact toxicity to 3rd - instar and 4th - instar larvae, and stomach toxicity higher than contact toxicity. But the stomach toxicity of indoxcarb to 4th - in- star larvae （LC50, 2.69 mg. L-1） was higher than that to 3rd -instar larvae （LC50, 3.-65 mg. L-1）. Indox- acarb has activation previously and inhibition afterwards to the activity of carboxylesterase, and the effect was stronger to 4th than to 3rd - instar larvae. The results Thdicated that the sublethal dosages （ LC10, LC30 and LC50 ） of the indoxcarb had an obvious impact on pupation rate, pupal weight, emergence rate and offspring sur- vival rate of the S. exigua, the influence degree was ranked as LC50〉LC30〉LC10