Photo by Drees. A hackberry gall psyllid, Pachypsylla sp. Photo by Drees. They can be carefully cut open to reveal the pale, developing psyllid inside. Immature stages of these species, when carefully dissected out of galls, appear maggot or grub-like and have no legs or antennae as do psyllid immatures.
Adults mate in the spring and females lay eggs on the underside of expanding leaves.
Nymphs hatch from eggs in about 10 days and begin feeding, which causes leaf tissue to expand rapidly into a pouch or gall around the insect. One generation occurs annually. Galls formed by these species are unsightly and occasionally cause premature leaf drop, but they do not appear to harm the health of the trees. None, not considered a major pest. For additional information, contact your local Texas extension service agent, or search for other state extension service offices.