Question
We have an oak tree in our front yard (in Austin, TX) that is about 30 inches in diameter. The previous owners cut a large limb (about 10-12 inches diameter)of the tree off several years ago. We beleive that they did not seal it properly because there are black spots on the exposed wood. Below the exposed wood it looks like some of trunk is lighter in color and when we remove pieces of bark we see several different types of insects like ants, roly polys, and what we think are curled up catepillars or centipedes. Above, there are lots of healthy branches and a few dead branches that are missing thier bark and don't have leaves. We think the tree is rotting from the unsealed wound, but are wondering if there is anything we can do to try to save it? Or if there is any way to tell how bad the damage is? Thank you!

Answer
I would just clean the loose bark off and spray the area with an insecticide. Liquid Sevin would work fine but there are other insecticide that will also work. Check with your local nursery for an insecticide for tree trunks (borers etc.) Do not worry about sealing the wound the tree will grow over the wound with time. As long as the foliage is green and healthy looking there is not a problem. The only thing that could happen is the tree over time (10-20 years) could become hollow but that in itself will not effect the health of the tree.