利用微生物防治农林害虫,在本世纪初曾受到重视,但在1938年发明了滴滴涕有机氯杀虫剂以后,人们就把希望寄托在化学农药上,生物农药逐渐地遭到冷落。由于化学农药的大量使用,不但使害虫产生了抗药性,而且造成环境污染,给人类带来了一定的危害。于是人们在寻找低残毒、不污染环境的农药时,又想起了微生物杀虫剂。微生物杀虫剂是指细菌、真菌、病毒、昆虫激素等生物农药,由于它不污染环境,又称安全农药。它具有来源丰富、不易产生抗性、选择性强等优点,被誉为“第三代杀虫剂”。这类杀虫剂的杀虫原理就是从自然死亡的害虫体内分离出病原菌,经过人工培养,再喷洒到作物上,使害虫感病致死。这种方法简单省力、花费不大、行之有效,最大的优点是这些病 The use of micro-organisms to control pests of agriculture and forestry was valued at the beginning of this century. However, after the DDT organochlorine pesticide was invented in 1938, people placed their hopes on chemical pesticides and their biological pesticides were gradually neglected. As a result of extensive use of chemical pesticides, not only the pests produce resistance, but also cause environmental pollution, to human beings have brought some harm. So people looking for low residue, non-polluting pesticides, but also think of microbial pesticides. Microbial insecticide refers to bacteria, fungi, viruses, insect hormones and other biological pesticides, because it does not pollute the environment, also known as safe pesticides. It has rich sources, not easy to produce resistance, selectivity and other advantages, known as “the third generation of pesticides.” The insecticide insecticidal principle is to isolate pathogens from naturally occurring pests, cultivated and then sprayed onto crops to kill pests. This method is simple and effortless, inexpensive, effective, the biggest advantage is that these diseases