Resistance of Insect to Pathogenic Viruses

家蚕核型多角体病毒(NPV)与家蚕血淋巴孵育后灭活。失活活性存在于相对分子质量为5kd的组分中，大于5kD的组分中存在该活性的抑制物。该组分经加热和蛋白酶处理后仍保持失活活性。我们还检测到谷胱甘肽对NPV的灭活作用，并正在通过血淋巴和其他化合物分析NPV的灭活机理。在对感染斜纹夜蛾的核型多角体病毒(NPV)的生物活性研究中，随着幼虫年龄的增加，半数致死剂量(LD50)和半致死时间(LT50)值增加。幼虫。LD_(50)值和LT50随幼虫日龄的增加而增大。孵化后11日龄以上的幼虫，即使在试验的最高剂量下，也不会通过口服接种感染。然而，将NPV注射到成熟幼虫体内后，由于病毒感染导致死亡，表明幼虫缺乏敏感性可能是由于幼虫接近化蛹时形成的肠道中介屏障所致。

Nucleopolyhedrovirus (NPV) of the silkworm was inactivated after incubation with the silkworm hemolymph. Inactivation activity was located in the fraction that passed a filter with 5 kd M.W.and inhibitors of that activity existed in the fraction with more than 5Kd. Inactivation activity was retained after heat and protease treatment of the fraction. We also detected that glutathion inactivated NPV and are analyzing inactivation mechanism of NPV by the hemolymph and other compounds.An increase in median lethal dose (LD50) and median lethal time (LT50) values with increased larval age was recorded in bioassay studies of the nucleopolyhedrovirus (NPV) infected Spodoptera litura Fab. larvae. The LD50 values and LT50 increase with increased larval age. Larvae those were more than 11-day-old after hatching was not infected through oral inoculation even at the highest dose of the trial. However, intrahaemocoelic injection of NPV into matured larvae resulted into death due to viral infection indicating a lack of susceptibility possibly due to gut mediated barrier that developed as the larvae approached pupation.