By: Peggy Tolboom
Have you been out in the woods and saw something like this?
Or leading a nature hike and someone asked you about this?
These are galls. It is made by a wasp, laying her eggs in a certain part of the tree. Then the tree builds the gall around the egg. This does not hurt the tree. The wasps are an important part of the food web.
One example is the Oak Apple wasp. The female wasp injects an egg into the veins of the leaf. The plant forms the gall around the egg. The gall is green. When the adult exits by making a hole in the gall, the gall turns brown.
There are hundreds of insects that produce galls. Each insect has a specific part of the plant to put its eggs. For example, on the top of the leaf, on a vein, or on the petiole.
