使用煤焦油乳剂防治落叶树上的越冬害虫或虫卯,至少已有六十年的历史。煤焦油为钢铁工业的副产品,我国从前在钢铁生产上极其落後,副产煤焦油的生产当然也极有限。果树病虫害的防治也不被重视,因此在国内从未见有使用煤焦油乳剂防治虫害的报导。煤焦油的重油和蒽油部分对於越多的介壳虫、蚜卵等有 It has been at least sixty years old to use coal tar emulsions to control overwintering pests or insect pests on deciduous trees. Coal tar is a by-product of the steel industry. In the past, China was extremely backward in steel production. Of course, the production of by-product coal tar was also extremely limited. Prevention and control of pests and diseases of fruit trees are also not taken seriously, so there have been no reports of using coal tar emulsions to control pests in China. Coal tar and anthracene oil part of the more for the scale insects, aphid eggs and so on