梨木虱原是北方果园的害虫，南方很少发生。近年来在上海市闵行区、青浦、南汇等县均有发生，部分果园损失严重。梨木虱主要为害梨树叶片，刺吸汁液。叶片受害率可高达７０％以上，受害叶片先变黑，叶柄变短，最后枯死脱落，同时果形变小，色泽差，影响商品价值。由于受害... Pest lice is a pest in the northern orchard, rarely occurs in the South. In recent years, Minhang District, Shanghai, Qingpu, Nanhui and other counties have occurred, some of the orchards suffered serious losses. Pear lice are the main damage pear leaves, sucking juice. Blast damage rate can be as high as 70%, the victim leaves darken first, the petiole becomes shorter, and finally died off, while the smaller fruit shape, poor color, affecting the value of the commodity. Due to the victim ...