Dendrobium Blight?

[ampaud]

Hello everyone! I need a little help.

Every time I have purchased a Dendrobium, they have always looked great, nice and green, pseudobulbs plump, and no signs of pests. I always check existing blooms (if there are any) for streaking so as not to bring viruses into my home.

However, every time I bring them home, they seem to be affected by the same disease. I have now lived in two homes and make sure to keep my plants quarantined if they are newcomers. The first time this happened, I had acquired a Little Atro Dendrobium that was just beautiful and had lots of blooms - and the leaves just started showing yellow areas and spots. The spots quickly spread from leaf to leaf, and eventually killed the plant, as well as the Bruce Gordon that I stupidly kept nearby at the time.

Now, I am smarter and generally a better cultivator, so I was brave when I picked this one up last week. She was gorgeous, had nice, tall flower spikes and everything looked ok, her leaves just needed to be washed. And what do you know - - but the spots are here! This time I was wise enough to take a picture.

What is this?? Is there any way to identify it on a plant before I purchase it? Is there anything I can do to stop it from spreading? I am including pics of the flowers, the most recently impacted leaf top and bottom, and the leaf above it (the infected leaf looked like this healthy leaf just a day ago, then last night I saw the spots!)

Thank you!!