１发生为害情况 柑桔红蜘蛛和黄蜘蛛是奉节县 ５ ４００ｈｍ２脐橙上的主要害螨。根据植保站测报统计，１９９０～１９９９年，害螨发生偏重以上的频率达９０％，近３年均属重发生年，对我县柑桔造成了严重为害，常年发生面积４１００ｈｍ２。据调查，桔园红蜘蛛最高平均百叶螨 1 Harmfulness The citrus red spiders and yellow spiders are the major pests of the 5 400 hm2 navel orange in Fengjie County. According to the statistics of Plant Protection Station, from 1990 to 1999, the incidence of pest mites was more than 90%. The occurrence of pest mites in recent 3 years was a re-occurrence year, causing serious damage to citrus in our county. The annual pest occurrence area was 4100hm2. According to the survey, the highest average citrus spider mite spider mites