Insecticidal soap has limited usefulness against nymphs. Consult the labels for dosage rates and safety precautions. Predators, such as green and brown lacewings, minute pirate bugs, ladybird beetles, and spiders, may control populations of the pear psylla. Pear sawfly or slug , Caliroa cerasi. This insect often defoliates young pear trees.
Sawflies damage the leaves especially on young trees.
May. Females insert eggs into blisters in the leaves. The green slug-like larvae eat the upper surfaces of leaves, often skeletonizing them. After feeding, the larvae enter the ground to form pupae. Adults emerge again in July and August, and the females lay the eggs of a second generation. Pupae of the second generation overwinter in cocoons.