Help Yellow Leaves on Dend.

[AnnieDN]

Please help. My dendrobium was seemingly doing well when all of a sudden the blooms dried up and fell off. Then the leaves started yellowing...but in this odd way with strips of green down the middle. See attached photo.



I cut off the yellowed leaves, pulled it out of the pot and did find the bottom of the pot soggy. I'm cutting the bad roots and am going to try and sphag and bag. But I'm concerned that, given the odd way the leaves are yellowing, that I may be facing a bug of some sort.

Any advice would be most welcome!