Leaf Damage on Miltoniopsis

[fishmommy]

What is this? It is not raised or pitted.

[orchidsarefun]

looks like a bacterial/fungal infection. I would spray with physan20 ASAP. In fact you should be preventive spraying monthly anyway. I find milts and other soft/pliable leafed orchids susceptible. Funnily enough when they are outdoors in Summer they seem fine.

[silken]

I get some of that on my Milts too. It likely is a bacterial/fungal infection but I suspect it is brought on by too much heat. At least mine get more than they should in the summer and this always appears after that. Same with my Masdies. I hope this summer will be better.

[NYCorchidman]

Most of my miltoniopsis have leaves affected with such spotting although not as many and concentrated.
Many of them are not very apparent as they are light green/white under bright light. Some turn dark looking yours in the pictures.

I have no idea what they are, but not baterical as they do not spread. They just show up and stay.
My personal take is virus and I'm going to get one of my affected miltoniopsis checked for virus soon.

I either trim away the affected leaves or dump the plant. I just don't like to see that kind of stuff on anything. lol

Over the period of last two years, I've been observing what kind of miltoniopsis are offered in the stores in my city and I only kept the ones I don't see often or never again. Fortunately, two of my favorites have clean leaves.