May 20, 2020
A "Galling" Question
What in the world is this?!? Could it be an acorn, maybe a hickory nut, animal scat or a strange rock?
It is an insect gall found on the branch of an oak tree at Lichterman Nature Center. Galls are abnormal growths that occur on leaves, twigs, or branches of different tree species. They may appear as simple lumps or more complex structures ranging in color from plain brown to brighter colors. There are about 1500 species of gall producers, the majority of which are insects and mites. Some galls form where insects or mites feed or lay eggs. The walls of the gall are structurally strong, rich in protein, and provide the larvae inside with food and protection. Sometimes galls also develop as a response to infections by several kinds of fungi, bacteria, and viruses. Galls affecting leaves are seldom if ever a serious problem. In most cases, galls are not so pretty but do not damage the tree. These pest organisms are specialists in forcing the host plant to provide food and shelter for the larvae which resides inside. To learn more about galls and many tree species, bring your class to the Nature Center for the newest Nature Lab, Tree Science. Identify trees using dichotomous keys to decipher leaf, bark and size differences. Use Forestry tools to measure tree height, circumference and temperature of a tree stand along forested trails. Record data to analyze in the lab classroom to determine board feet and health of the overall forest stand. One…two…tree…let’s go!