What is this under leaves?
 

It's only on this, milt. Fitch. And only on a few leaves. Is it a virus or pest? What should I do? I've isolated it.

Oops, photo.

You can't tell virus by looking ! Sorry, but your pix is too small to distinguish anything.

It's hard to tell from such a small photo. Can you post something larger?

Sorry, I posted using Tapatalk on my cell phone. I'll have to get my computer hooked up and running today - just came back from the shop yesterday. I'll repost. In the meanwhile, it reminds me of red rust. But when I rub my finger across it nothing comes off. It's almost as if the cells have collapsed and left red markings.

You've got spider mites.

WOW Glen, you have got eyes like a hawk! But I suspect you have seen that marking before. :rofl:

You can spot many common viruses on plant leaves as the virus develops. That does not mean you can spot them all and a plant can test positive when it does not show symptoms. Just a clarification on that point. :twocents:

Cym Lady

That is a confusing statement. Yes, you can see what you THINK is a virus but that is NO proof that it is ! I've seen hundreds, literally, of virused plants and you can also see ones with color break on leaves and on blooms that test NEGATIVE. There is NO WAY to tell by sight. You can SUSPECT by sight but you'll never know until you test. I'm talking about ORCHIDS here not any other plants. There are only 3 viruses "common" to orchids and those are the ones I'm talking about here.

Yes, Chryss is right..the only way to prove virus in orchids is only by testing.

Glen ...your eyesight is astute...I think its mites too...reddish colony on the back of the leaves...and look for weblike silvery threads too...and sticky liquid on the surface of the leaf

quick remedy:

10 drops dish soap
1/2 teaspoon cinnamon extract
2 cups tepid water

spray the plant soaking wet
make some more to soak the pot and media for five minutes to kill the eggs
repeat this the next week and then have a two weeks rest then repeat

There are no webs, though I've read you'd also see that when it was bad as opposed to just starting. There is also no sticky substance. I will try your remedy bud. Any other thoughts?