Pear slug

You will find olive-green, slug-like larvae with glossy slime coating on the upper leaf surfaces of pear, cherry, hawthorn, and mountain ash trees. Feeding damage creates a skeletonized appearance as larvae consume tissue between veins. Mature larvae are orange-yellow. Multiple overlapping generations cause repeated defoliation from late April through summer. Young trees suffer the most impact.

Remove infested leaves and prune heavily damaged shoots to improve appearance. Hand-pick larvae clustering on lower canopy leaves. Spray strong water streams to dislodge small larvae. Encourage parasitic wasps and natural enemies. Time applications for May and July targeting young larvae before heavy feeding. Dormant cultivation may reduce pupae. Avoid pesticides that harm beneficial insects.