Hackberry gall makers - Extension Entomology
Description. Nipplegalls are one of the most common gall-making insects on hackberry. Hackberry trees are host to a variety of gall-making insects. One of the most noticeable and common species is the hackberry nipple gall, a type of psyllid (SILL id) insect. Nipple galls appear as 1/8 to 1/4 inch swellings of tissue on leaves or petioles.