Reactivation of Latent Nuclear Polyhedrosis Virus in Silkworm

Abstract

Viruses, especially in latent state, are widely held to be beneficial such as in the silkworm, and in insect pests which seriously damage crops and forests. Sometimes a virus can be passed on from one generation to another for a very long period of time, remaining inactive and harmless to an insect. Ecological and other stress factors may activate a latent virus (Aruga, 1963). Sometimes a latent virus is activated spontaneously, which causes a disease in an insect or its death. Thus, latency underlies viral regulation of the insect population.