梨木虱的发生与防治梨木虱是梨区的主要害虫之一。该虫春季多集中于新梢、叶柄为害，夏秋多在叶背取食，成虫及若虫吸食芽、叶及嫩梢汁液。受害的叶片发生褐枯斑，严重时全叶变褐早落。新梢受害有萎缩现象，发育不良。若虫分泌大量蜜汁粘液，诱致煤烟病。因梨木虱食性单一... Occurrence and control of pear psylla Picea is one of the major pests in pear area. The spring insects and more concentrated in the shoots, petiole damage, more summer summer back feeding, adults and nymphs buds, leaves and shoots juice. Occurred brown spots withered leaves, severe browning when the full leaves fall. Shoot damage new shoots, dysplasia. Nymph secretion of a large number of honey mucus, causing soot disease. Due to the pest lice single ...