Damage/Symptoms:

Damage consists of wart-like growths on the bottom sides of leaves. Leaves may only be affected on a few branches.  

Cycle:

The psyllids remain in protected areas over the winter and emerge in the spring as buds are expanding to lay eggs on the undersides of leaves. Nymphs emerge from the hatched eggs and feed on the leaf. Raised swellings develop creating the protective gall, where they continue development and emerge in the fall.

Natural or Biological Controls:

Insects do not seriously affect the vitality of the tree; therefore, under most circumstances, control is not recommended.

Hosts:

Hackberry