Hackberry psyllids are tiny, jumping plant lice (family Psyllidae) that infest hackberry trees. Several species of psyllids infest hackberry. The most common is Pachypsylla celtidismamma. They resemble miniature cicadas (about 1/6 inch long) and are a dark, mottled-gray color
Hackberry psyllids are often called hackberry nipplegall makers because nipple-shaped galls about 3/16 inch wide and 1/4 inch high develop on the underside of infested leaves (Figure 2). The gall, an abnormal plant growth on leaves or stems, results from complex chemical interactions between developing insects and plant tissues. As a gall develops, it becomes a “house” where the immature insect resides. Most infested leaves contain several galls, and host trees apparently do not suffer seriously, although galls are normally considered unsightly.
Are you suffering from an infestation by Hackberry psyllids, .