Abnormal Growth on tree leaves - Ask Extension
Wondering what is causing this abnormal growth on the leaves of my new Common Hackberry Tree
Knowledgebase
Abnormal Growth on tree leaves #771459
Asked September 14, 2021, 1:26 AM EDT
Wondering what is causing this abnormal growth on the leaves of my new Common Hackberry Tree
Aurora County South Dakota
Expert Response
This is a gall made by a small insect (a psyllid), that lays its eggs in the leaves, the nymph uses chemicals to get the leaf to create a protective coating and the grown insect later emerges. This isn't detrimental to the tree, just unsightly but extremely common.
https://extensionentomology.tamu.edu/insects/hackberry-gall-makers/
