Is it stubborn scale? Or is it edema? A common issue I have seen in the Nelly Isler
 

Hey everyone!

I made a video discussing edema/blistering on orchids, and I have noticed that it is actually pretty common in the Nelly Isler orchids I've seen.

Scale insect is wiped away pretty easily with rubbing alcohol, and if it won't rub away no matter how hard you try, it may in fact be blistering instead!

Edema is caused by overwatering plants with temperatures that are too cool. Nelly Isler orchids have blooms that are influenced by temperature, producing much prettier, redder blooms in cool temperatures. Nurseries are excellent at hydrating their plants, so I hypothesize that these orchids have this edema as a common problem because of nursery growing styles combining with a need for cool temperatures to produce the most beautiful flowers.

So before you maim your plant and bust out your gas mask to kill the little scale insect, consider it may actually be edema instead, which is not contagious to other plants and doesn't need to be treated.

Scale can spread to your other plants, and will spread more widely on the main plant that has it.

Edema may or may not spread more widely on your plants. Here is my idea why it doesn't spread: Nurseries have ideal settings, so the plant is easily getting lots of water. At home, we likely water a lot less than a nursery, so the plant is far less likely to blister/experience edema.

Here is a paper on edema in orchids.

And I have made a video showing the issue, which you can watch below to hear my full opinions and see examples:

I have seen sooo many Nelly Isler and I have not seen anything like that.

I don't think that looks like a blister at all. or perhaps because I can't really see exactly what they look like but in the video, those tiny dark spots look rather flat.
If you google orchid edema, it will be like a bump literally like a blister.

The leaf you are holding in the video looks to me it has mites damage.
Those dark spots, and then I see silvery rusty appearance all over the underside of that leaf.
Do you see any mites crawling around??

No.
The spots aren't flat, they're like little bumps. They're like a smaller version of the spores that grow on the undersides of ferns. They definitely are raised. The silvery leaf became silver due to firmly rubbing it with rubbing alcohol (at least I think so, because that is what happened to my plants when I did it and this one from the nursery looks so similar).

I'm going based on the paper that I linked, as well as the images I can find around the net. See the bottom few pictures here:
Images of Edema on Orchids

I would literally freak if I saw mites running around!! I had this issue on my first two nelly islers and never saw a single mite, but I still had this issue.

The images of mites damage I am seeing online are all showing as depressions on the leaves, but mine aren't depressed.

Interesting point of view you've brought up! I am not counting anything out, but I feel quite confident in my ideas, and at least that I don't have any insects pestering my plants.

I just saw this cool microscope that connects to your computer on MissOrchildGirl on Youtube, you can really see the leaf tissue, mites ect. I ordered one. That way I will know what's really going on in there!

Ok, I cannot see if they are raised in the video, if they are bumpy as you say and they do not come off when scratched with nails or some other tools, then I guess it's just harmless "skin" issues.

Regarding the leaf surface turning silver after applying alcohol, that is interesting!
I have applied alcohol on many things, but never seen any change.
I did see silvery rust look on the underside of one of my dendrobiums when applied hydrogen peroxide.
So I guess it really differ by plants how they react to what.

Hello folks,
I am not sure but I have been dealing with something like this for while now. I treated many plants thinking it was scale. This has shown up on my Catts, oncids, ondontos, and Cyms. The Cym I just got 1 week ago was fine except overly water when I got it. I am at a loss I grow indoors and have a room dedicated to the collection but Cym I have trying to keep outside. Well brought it in 2 days and it had these same little thing. It all stems from a little brown spot, then a halo ring forms around that here are some pics. This is the Cym in question. I was gonna ID this plant but noticed this thread. I will have to make multiple posts to see what's going on
Plz help I have destroyed many a leaf trying to fix his

This is normal magnification and is what you see

This is at 60x mag

This at 100x magnification

Hey matorchid, maybe you should start a new thread to ask your question?
Jumping on mine is going to get a bunch of replies that aren't relevant to my post, and it may prevent you from getting responses you want because it is not its own thread.

Please make your own post.

Hello Astrid,

I will. I just thought that I was dealing with same thing and just kinda wanted some opinions or poll on next step of action. It seems like the same as I watched the video and everything that was stated in it is the same. I am sorry and didn't mean to hijack your thread
By the way have you found a solution to this problem? Cause inquiring minds would like to know, LOL.
Again my apologies. Have a wonderful weekend.

It's okay! I hope I didn't come off too grumpy, but it's almost always better to start a new post, I think. :)

I don't consider the leaf spots to be a problem, really. They are (in my opinion) just little blisters on the leaves that cause only minor cosmetic issues and do not harm the plant. So there's nothing to do but to wait for old leaves to be shed and new leaves to come along, and enjoy the flowers in between.

Let me ask this of you. The spots that your seeing are they surrounded by a halo. It was hard for me to see. Did they look like the pics that I have taken of my plants? The reason I ask is on some of mine the number seems to grow while others don't have any of those spots.

I mean, the spots on my plants' leaves do have a little "halo" around them where it looks like the leaf is more transparent.

But for me, the bumps are raised and have some texture, and are impossible to remove without really hurting the leaf (think: picking them off with a needle).

I have heard that other things the black spots might be include a minor fungal or bacterial infection, small sunburns, and so on. It could also be scale insect, but those are definitely raised bumps on a leaf and should be easily removed with alcohol. I think it's often really hard to say.

I think you should keep an eye on the plant. If the problem spreads or you start to notice insects or something, you may figure out what it is. I would keep it away from other plants until you know what is wrong.

Ok I was just trying to pick your brain a little. I didn't think it was scale and tried those methods I even pulled out the razor knife to try to pop off the caps make it easier to remove but that didn't work that actually it ended up destroying the leaf. And these to, are raised little bumps and they do seem like they grow in number on one of my plants it seem to increase and has since died off a little.I don't know if it was the conditions or what so I was just picking your brain.
The plant you see in the pictures is not even with my collection inside the house, it's actually one I keep outside, and is new to the collection altogether about a week old. So I will let you go and again on my apologies, have a good weekend