We have an oak tree in our front yard that is losing patches of bark and has many holes in the bark from an insect or a woodpecker I guess. The tree also has a big plug of mistletoe growing out of the side of the tree about three feet from the ground. Last year the tree was so filled with aphids that it dripped sticky sap on my car all summer and fall untill all leaves were lost. Very messy. This tree is getting some leaves now but seems behind the other trees in the neighborhood. Sould we cut it down and plant something else or should we try to save this tree instead? If so, what can we use to heal it and to rid it of the aphids?