昆虫流行性病害常是害虫大发生终止的原因。许多林木害虫也都有这种现象。当舞毒蛾、松毒蛾、松夜蛾等害虫大面积爆发毁林以后,常因病害流行而大量消亡。人们由此产生人工传播病害的思想。初始正是对上述害虫运用了各种简单侵染传播法,如把已感病昆虫放入林中,将病虫的尸体和带菌的枯枝落叶层运送到不发生病害的林区,甚至把染病昆虫磨碎成粉 Insect epidemic disease is often the cause of large pests termination. Many forest pests also have this phenomenon. When Gypsy moth, pine gnats, pine and other large pests erupted deforestation, often due to the epidemic and a large number of death. People have the idea of ​​transmitting the disease by hand. Initially, various simple methods of infection propagation were applied to these pests, such as putting infected insects in the forest, transporting pests and carcasses and carrying litter layers to non-disease-affected forest areas, Infected insect grind into powder