The photos that Dennis Norton pointed to look remarkably like what I've
seen on my peach trees recently. I had sprayed with a standard home
orchard spray, but just discovered yesterday when I reached the bottom
of the spray container that there was a big mass of solidified white
stuff at the bottom, which is probably what was supposed to be taking
care of the nasties on my trees. I hadn't used the spray before, and
while I was surprised by the color (looked pretty much like a "sticker
oil"), I didn't know that it was a sign of a problem. I had agitated the
spray container, but wasn't expecting that there would be a big fairly
solid lump at the bottom. Must have been pretty old.
Live and learn. :-(
On a separate topic, I have found exactly one Asian pear. All the other
flowers and young fruit got zapped by the freeze. On a more positive
note, all the plants seem to be in good shape.