What caused the damage found on a dead branch of this peach tree?
This damage was caused by a shothole borer. Shothole borers typically find a way into the wood through damage initially caused by sunburn or bark injury. Adult females bore into the bark and lay their eggs in the cambium layer of the tree. Eggs hatch, and larvae feed their way to the surface. This feeding can cause girdling and death of the branch/limb. Protecting young trees with tree wrappers can help reduce damage. Read more about shothole borers here.