多年来,防治蚊、蝇幼虫都采用化学杀虫药剂。蝇蛆生活在有机质丰富的垃圾和粪便中,孑孓生活在污水中。由于这两类孳生环境中各种细菌、微生物极丰富,许多化学杀虫药剂在微生物、水分和阳光作用下。很易分解失效;另一方面,垃圾和粪便又常用作肥料,一些污水可能被雨水带到河流、湖泊和鱼塘中,污染水源,对人、畜和鱼类造成危害。因此,毒性大的化学药物不宜用来防治 Over the years, prevention and control of mosquitoes, flies larvae have adopted chemical insecticide. Maggots live in organic matter-rich litter and excrement, which live in the water. As these two kinds of breeding environment in a variety of bacteria, microorganisms very rich in many chemical pesticides in the role of microorganisms, water and sunlight. On the other hand, garbage and excrement are often used as fertilizers. Some sewage water may be brought into rivers, lakes and fish ponds by polluted water to pollute the water and cause harm to people, livestock and fish. Therefore, toxic chemicals should not be used to control