Picture of Nipple Gall
Nipple Gall

Picture of a Hackberry Gall
Hackberry gall

Picture of a Hackberry Gall psillid
Hackberry gall maker

Picture of a Hackberry Gall Psillid
Hackberry gall maker

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Hackberry nipple gall psyllid

Galls appear as 1/8 to 1/4 inch swellings of tissue on leaves or petioles. Adults resemble tiny (3/16 inch long) cicadas.

A number of psyllid species occur on hackberry, including the hackberry nipple gall maker, the hackberry blister gall maker, and the hackberry bud gall maker. Galls are unsightly and occasionally cause premature leaf drop, but they do not appear to affect tree health.

Life cycle:
Common leaf gall forming species overwinter in the adult stage in bark cracks and crevices. Adults mate in the spring and females oviposit 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. They develop through several instars before emerging as adults in the fall (September). One exception is the hackberry bud gall maker that overwinters inside the gall as a last 5th instar nymph and emerges as adults in early summer. One generation occurs annually.