Milty Malady
 

....This morning I discovered this on a leaf of my miltoniopsis herr alexandre. The plant lives under a skylight near a mirror in a bathroom and has the longest bloom of any orchid I own (4 months!). It's getting a little less light now due to the direction of the sun shifting.

6 Months ago I'd seen something similar over a few leaves of an oncidium alliance plant that also started getting less light at the time (withered but subsequently survived by way of new growth). At the time I wasn't sure if it was calcium from fertilizing or a virus (but I assume calcium would be on all leaves).
Help.

:bump:

...Any ideas from the viewers? Guesses even? Thank you! I wonder if this is very oncidium alliance specific

I have several Milts but can't say I've seen markings that are exactly like that. Onc. are prone to spotting and I do get some Milt leaves and other Once. with lighter green blotches sometimes. I've never known why so I'm not much help.

Have you checked for pests and spider mites! It seems so specifically along the edges of the leaf. Also I have heard that Milts have very sensitive roots and are light feeders. So maybe too much of something in the plant food? Sorry, it's all I can think of.

There are several areas where the damage looks like a mirror image on both sides of the leaf. I am suspecting physical damage rather than a pest...... Maybe a bent leaf, pinching or accidental gouging with a stake or a name tag while the growth was small?

Thanks for your feedback and observations. I had an oncidium with the exact same markings about six months ago, so I'm thinking it would have to be a coincidence if the culprit was due to a physical insult. The two of them are in proximity to many other orchids, but not to each other, and none of the others have had this issue. I'm not sure if the pictures are clear enough. It's almost as if these spots are like plaques of some sort where there is a clustering of the leaf's flesh to one spot (but clearly not scales). My fear is that this could be a virus but again, none of my other miltonias or oncidium nearby have it...So that leaves me with nutritional, but still weird!

I guess you could try some bacterial, fungal treatment.

Kinda looks like the griddle marks on some of my plants.
https://lh5.googleusercontent.com/-n...o/DSC_0035.JPG.

They got fried from the pattern on the window.

I sure hope that's what it is! My worry is that not all the spots show a loss of color (some are fully green). In the first pic you might be able to see that they are also a bit "fleshy" (like the flesh of the leaf bunched up in one area that forms each spot). They're most accurately described as plaques, I think. They DO seem to be higher toward the tips and not so much toward the base of the plant (meaning the sun is influencing?).