Disturbing leaves on D unicum and D Delicatum

[Harris E.]

Hi Everyone

Just a couple of days ago I noticed some leaves yellowing on my D unicum. I wasn't too worried since it had been getting a lot of sun recently so I just moved it to a shadier spot in the greenhouse. I took another look today and the leaves really look bad - much worse than before. Please see the first two pictures I attached. It seems to be affecting all the leaves on the plant including the ones on the new growth. To top off the bummer, the same thing is beginning on my D. moniliforme which hangs above the unicum in my greenhouse. Has anyone seen this before?

Also I found a brown ring surrounding a brown lesion on my D Delicatum leaf (see third picture). Any chance this isn't a virus?

Yuck.

Harris