Eastern Speckled Oak Gall

What’s that ball on the tree?

They are galls caused by a tiny wasp commonly called a cynipid gall wasp.  There are many species and most of them make a distinct gall.  These galls are probably caused by Loxaulus maculipennis.  They are basically harmless to the tree.  You can cut one in half and find fibrous filaments extending from the outer shell to the center core.  Inside the center core will be a tiny larva which will eventually pupate and emerge as a tiny wasp.  The wasps are seldom seen and they do not sting.

Here is a link for some information.   See page 102 and 103


http://www.flickr.com/photos/damon_tighe/7363279198/ (inside of the gall)

Joe Pase, Texas Forest Service, 936.639.8170