What's your question? Ask

You might take some of the leaves to your local extension office to more clearly identify what you are dealing with. This sounds like a fungal infection of some sort, but they will be able to better tell you exactly what it is and the best methods to treat the problem.
Good luck

It sounds like it may have a fungus. Treat the tree with a fungicide and this will kill the fungus. It should try to grow its leaves once the issue is resolved, but may not have time before fall comes. If this is the case, it will need extra care and protection to make it through the winter as its energy reserves will be low.

Sorr you have not gotten an answer on this. We had a red foliage plum tree that seeded but only close to the tree. We cut it down five years ago and still have "seedlings" popping up. Pulling them is nearly impossible so I just cut them off at ground level. Eventually they will all give up since they can't produce enough leaves to support the roots.

This can happen for a number of reasons. Fungus, pests or watering issues are the most common. Treat the tree with a fungicide and a pesticide to take care of the first two possible issues. For the watering issue, make sure the tree is getting at least 2'-4' of water a week. But also make sure it is not in standing or overly wet soil, as this can cause root rot, which makes it difficult for the tree to take up water.

If you do not see any evidence of disease, the tree has simply reached the end of its life. 15 years is the expected life span.

They are likely apple maggots, which can actually affect most tree growing fruit. This article describes how to control it on apple trees, but the methods are the same for all fruit trees: http://www.extension.umn.edu/distribution/horticulture/DG1007.html