Sounds like it is possibly fire blight. Check your Ortho Book for more info.
If it
is, you have to remove all the infected branches and spray with something like
copper sulfate. It's a nasty problem, and could spread to other nearby plants
if
not contained.

Sherwin D.

Fish wrote:

I planted a very small prunes few month back, it grew 2 feet strongly
and suddenly it started to developed some type of disease in southern
calif.

the leaves have small holes in it, they are droppy, many become
yellow. Most have holes except
the young one.

I use Ortho Garden Disease Control, no good. Use different product to
keep insect away, no good.

Go to nursery, they point me to different directions depending on whom
I ask, they are few time more expensive than the tree itself.

the branches become darken as if they have fungus infection, but buds
grow on them.

see some flies who use the leaf as bathroom or nursery for the young.

Out of wit, anyone who has idea what happened to the tree and how to
cure it?