(续 1991年4期 33页) 梨木虱是梨树的一种重要害虫,在我国北自辽宁,西至陕西、南至四川的梨区均有为害。主要刺吸花丛、新梢、叶柄、叶片及果实的汁液,使花及果梗凋萎变黑掉落、使叶片向背面反卷,其排泄粪液有粘性,可诱发煤病,引起大量落叶。秋季时此虫常将叶片粘附于果实上,在 (Continued from 1991 4 period on page 33) pear psylla pear is an important pest, in our country from north Liaoning, west to Shaanxi, south of Sichuan pear area are harmful. The main thorn sucking flowers, shoots, petiole, leaves and fruit juice, so that flowers and fruit stalks wither dark fall, so that the leaves back to the volume of the paper, the excretion of manure sticky, can cause coal disease, causing a large number of leaves . In autumn this worm often leaves attached to the fruit, in