If that is the stem with all the browning, have you considered a borer?

Looks more like something eating than a virus. FWIW, I was just reading an article on Spider Mites and read that the use of Pyrethrin may very well make it much more likely you'll get them because Pyrethrin kills most everything that might eat Spider Mites.

Cheers,
Russ

No thats not the stem that's brown, I just think it's time for me to buy a new camera.

I agree with you Russ. If you've ever read the Pyrethrin instructions, you can be assured it's just as toxic to humans and beneficials as the "non-organics". But I've been shooting the dahlias with soapy water and it doesn't seem to be working.

And thank you. Based upon your observation I went back to the WSU website and admit their mottling doesn't appear to have the amount of dieback I am getting around the edges nor can I find the same patterns of mottling they mention. But it may be a mute point because the virus's are generally spread through aphids and leafhoppers.

I have found a few leafhoppers and a few aphids but not enough to explain the pathetic condition of this plant so I am still wondering...