Garden Pests and Diseases: Friend or Foe #7, 0 by Night_Bloom

Night_Bloom wrote:
A post in another thread reminded me of this interesting - to me anyway - group of insects: gall making insects. These fall under the "sort of foe, but not really harmful" category, and many of these galls are quite interesting to look at. Most don't do any lasting harm to the trees they inhabit. Oak trees are especially prone to getting galls.

Here is an example of one species of oak gall. These are called wood sower galls, and they are made by small wasps. Here is what the galls look like...