I am hoping someone might give some suggestions as to what is going on with my mature/large Weeping Youpon. This is the first spring that it is showing some kind of damage. The damage is not located all over the tree, but appears in sections. My guess is that the damage will cover the tree if left untreated.

The damage is to clusters of berries, clusters that form a kind of balled area of dark -- grey/black. It reminds me of honey-dew, but I'm thinking it isn't honey-dew because the darkened areas are confined to clusters of berries. It reminds me of a fungus because if I look close enough, there will be some white between a berry or more in the cluster.

This tree is the private residence of a beautiful singing Mocking Bird and his mate.

Just after noticing the damage (yesterday) I decided to prune all the damaged fruit and the Mrs. Mockingbird shouted me out of there.

Please help.