琯溪蜜柚煤烟病造成树体组织表面布满煤烟状物，影响光合作用，使果实变小、外观差、品质下降、商品价值低。该病于５至６月和９至１０月发生较严重。据调查，福建省平和县各琯溪蜜柚园普遍存在该病，发病率在３０％左右。该病是由蚧类及蚜虫等害虫的排泄物引起煤烟病菌的大量? Guanxi honey pomelo soot caused by the tree tissue surface covered with soot, affecting photosynthesis, the fruit becomes smaller, poor appearance, quality decline, low value of the commodity. The disease in May to June and September to October more serious. According to the survey, the county of Pinghu County, Fujian Province pomelo pomelo garden common disease, the incidence of about 30%. The disease is caused by the pest insects such as scale and aphids large amounts of sooty bacteria?