加拿大是利用昆虫病毒防治森林害虫的策源地。本世纪三十年代,欧洲云杉叶蜂Gilpiniahercyniae的危害,给加拿大云杉木材生产和纸浆工业带来了威胁。四十年代,一种核型多角体病毒(NPV)随着昆虫天敌从欧洲偶然地引入加拿大,自然传播引起流行病,将欧洲云杉叶蜂的严重危害有效地控制下去,并长期保留于环境中自然调节害虫,种群。此后,加拿大 Canada is the source of use of insect viruses to combat forest pests. The thirties of this century, the European spruce hornet Gilpiniahercyniae harm to the Canadian spruce timber production and the pulp industry posed a threat. In the 1940s, a nuclear polyhedrosis virus (NPV) was introduced into Canada spontaneously as predators of insects from Europe and naturally spread epidemics that effectively controlled the serious damage caused by the European spruce leaf bee and remained in the environment for a long time In the natural regulation of pests, populations. Since then, Canada