Shiva said:

My Peach tree, of about 8 years old, 7 feet tall, variety unknown, has
suddenly started bleeding sap from hundreds of tiny spots all over. Thne
leaves have all but dried up and fallen off, the ends of the twigs are
dead and dry too. This happened within days.
The tree is about 50' away from two others, and about 20 feet from
another peach tree, none of the others have the same problem.

I don't know if I can add pic here, which I took yesterday, so I put
them on a mini-page whrich you can visit by going to
http://www.westside.ca/peaches

Your tree is history. Destroy it immediately. Inspect the other trees for any
sign of peach tree borers. You will need to consider a spray program to
protect them. Sometimes the trunks of the trees are painted white to protect
the bark from winter injury and discourage borers from laying their eggs (they
prefer to lay eggs at cracks in the bark).

http://www.urbanext.uiuc.edu/bugrevi...treeborer.html

There are new approaches to control peach tree borers (using pheromones
to disrupt their mating) but I don't know how practical or available they would
be for the typical gardener.
--
Pat in Plymouth MI

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)