Insect and Spider Identification: OMG!, 0 by scatgo

scatgo wrote:
Well I think I found the problem that is killing the Magnolia I have in my back yard but I am not sure what those bugs are. I have lived in this house my hole life and have notice a problem with branches rotting at least 10 years ago but was never sure what the problem was till now. It is a large tree and has many new branches growing on it but I am not sure if I am going to be able to save it at this stage. The underside of the leaves are covered with these things and they are everywhere. What are they and what can I do about them?