Raspberry virus/disease help!

[Collector]

Something is working its way into our berry patch not sure what to do. We do not see any insects or anything that would cause the plants to start yellowing and dying back with fruit on the canes. It start with the leaves yellowing or getting spots on them, and ends when they are cut out because they are dead. We hope that the whole patch is not a total loss! Here is a picture of the spotting on the leaves.
If anyone knows what this is, and what can be done about it please advise!
This is a very productive patch, we would sure hate to lose it.

 

[digitS']

Just to start you off this morning, Collector, here are links to UCDavis links on berry pests & diseases: (LINK).

I have very little experience with raspberries. I know that they have hard to see mites in late summer. It doesn't look like a mite problem. I think of rust as a late summer problem also but see that there is something called "yellow rust" listed that attacks raspberries early.

You might want to take a close look at the yellow rust photo and see if it compares. There are copper sprays that are organic but I don't know if that is what they are advising. You might have to cutback infected canes this year and treat next year's canes but I don't know.

It seems to me that we haven't had any unusual weather that might cause this. I'm always willing to blame leafhoppers and such with spreading diseases ...

Now, we need someone with more knowledge of berries. @marshallsmyth may have ideas and help.

Steve