中文摘要：

以斜纹夜蛾核型多角体病毒（S1NPV）为免疫刺激因子，观察SlNPV对斜纹夜蛾幼虫酚氧化酶活性及其血淋巴黑化的影响。结果表明：斜纹夜蛾幼虫感毒后，其血淋巴黑化率在感毒1d后开始逐渐下降，随着感毒时间推移和幼虫日龄增大，病毒抑制其黑化作用增强；在感毒后连续5d观察时间内，感毒幼虫血淋巴黑化率始终低于健康幼虫，且在感毒4～5d后达到显著水平；感毒幼虫体内及其血淋巴酚氧化酶活性在感毒后前3d都是逐渐上升而后逐渐下降；感毒幼虫体内酚氧化酶活性在感毒后前3d高于健康幼虫，在感毒4d后开始低于健康幼虫，且在感毒2、3、5d后均达到显著水平；与健康幼虫相比，感毒幼虫血淋巴酚氧化酶活性在感毒2d后开始明显增强，但感毒5d后急剧下降。

英文摘要：

The influence of Spodoptera litura nuclear polyhedrosis virus （S1NPV） on the phenol oxidase activity and haemolymph black of the Spodoptera litura （Fabriciu） larvae was observed by using S1NPV as the immune stimulating factor. The results indicated that the melanization rate in the hemo lymph of the host Iarvae infected with SINPV at the early 2nd instar began to decrease gradually from day 1 after the virus infection, the ability of the virus in inhibiting the melanization was enhanced with the passage of time after the virus infection and with the increase of host day age; within the 5-day ob- servation time after infection, the percentage of melanization was consistently lower in virus-infection group than non-infected （healthy） group and this difference was significant on days 4 and 5 after infec- tion; in virus infected group, the phenoloxidase activities in the larval body and in the hemolymph of S. litura larvae gradually rose up in the first three days after infection but then dropped down; the phenol- oxidase activity in the larval body of S. litura larvae was consistently higher during the first three days but began to be lower from days 4 after infection in the virus-infected group than non-infected group, and this difference was significant on days 2,3 and 5; compared to that in non-infected group, the phe- noloxidase activity in the hemolymph of the host larvae in virus infected group began to be enhanced from clays 2 after infection but sharply dropped down on days 5 after infection.