Hmmm, yes, I originally clicked on photos when I first read this post, but this time I just looked at the thumbnails and it looked like what had happened to my plant. I went back and found my thread and photos. Mine was actually a violacea.

Mesophyll Cell Collapse
 

Manu, I agree. if the leaves closest to the lights are not suffering the same symptoms, it is probably not sunburn.

There is another possibility but before I bring it up, please go to the following website and read the article on Mesophyll Cell Collapse:

Mesophyll Cell Collapse

This AOS article tells you how you can distinguish between a Virus & Mesophyll Cell Collapse with the latter often not noticeable for 6 to 8 weeks after exposure. It also tells you to rule out thrips which can cause similar symptoms. Once you are sure it's not cell collapse or thrips, let us know. There is another possibility you can look into but let's rule out the above first.

Hey Sharon,

I don't have Thrips. I have some springtails and some hypoaspis miles feeding on them... Occasional fungus gnat in the summer but haven't seen those in awhile. I don't have any sap sucking pests.

As for the article I had already read it and others as well. I have 4 plants that have bad spots. 2 of them were neglected in October and could of faced some nights around 13C at the lowest for a few weeks. After that temps were restored. They both showed some spots and cell collapse a few weeks after. However, my Bellina and the Phal V3 that I posted the left right image of earlier today did not suffer any cold. In the worst case scenario they could of had some nights temps around 18 19 C back in October. The Bellina has been pushing out those yellow spots since October, it started as one or 2 and eventually the entire plant except the new leaf until it fully matures. Since those spots started, It grew 2 new leafs. The most recent one is still intact and a perfect shinniy green but is still growing. The other one that grew this winter was perfect until it matured, then it got those spots. The Phal V3 which is the one that I posted a photo of earlier today, didn't suffer any cold either, nothing happened that I can think of in the past 3 months...

So what is that other thing you got me all curious?

A member of the Big Leaf Orchids Forum posted photos of an infection involving her phals back in 2012. Within the post, a link was also included to orchidboard.com where additional photos of the diseased phals were posted.

There is a non-descript disease called a Microfungus. I don't think anyone has been able to identify the exact fungus that causes the symptoms but treatment with a systemic fungicide has sometimes worked.

Big Leaf Orchid forum • View topic - Lost Half of My Phal Collection

Microfungal Outbreak

I have no experience with this Microfungus.Take a look at the photos on the Big Leaf & Orchidboard forum sites & let me know if this more accurately describes the symptoms your orchids are suffering from.

Thanks Sharon
I saw those posts a while back and believe I am dealing with the same or closely related issue. I read it again and my understanding is that fungicide didn't fix the issue and everything was lost... Terri actually comes to the same conclusion then me. PhCSV or Potyvirus.... :-(

Thanks :-)

Reread... my understanding was that one person posting to the Big Leaf forum said that treatment with systemic fungicide did work, but did not say which one.

There is an image of a Phalaenopsis infected with potyvirus here:
Identification and characterization of a potyvirus causing chlorotic spots on Phalaenopsis orchids (PDF Download Available)

It does not look like your plant. I would try and take a piece of leaf someplace where they can examine it under a microscope to look for fungal hyphae in the tissues.

Yeah I know one person said that, I was referring to the conclusions of the owner of the plants in that post.

There's also someone else that states he knew this was virus and had the same issue and plants test positive to CMV and ORSV, which I know for a fact this is not my case as I tested those viruses already with Agdia immunostrips.

Ill try to bring my Bellina somewhere and have it checked out. Thanks

Microfungus or Virus
 

Manu,

How is your phal bellina doing? Did those yellow patches clear up, stay the same or did they develop pits and brown discoloration? Is there any similarities between the symptoms on the phal bellina and the photos you just posted?

From your most recent photos, I really do not see evidence of a virus. It really looks to me like either Mesophyll Cell Collapse or possibly sunburn.

You mentioned your orchids are all in bloom now. Are you seeing any indication of color break or streaking on the flowers which might confirm a possible virus?

You could have two problems going on at one time. I have to agree with estacion seca at this point. You really need to have the leaves tested.

Yeah I agree it might be 2 completely distinct issues, or could also be the same issue that affects different species differently.

The last photos posted were of a hybrid that I've had for about 5 years now. It has yellow spots that turned to cell collapse. This happened a few weeks ago for no apparent reason. It has large white flowers so hard to answer the color break question.

The Bellina has ongoing issues since about October 2016 when it finished blooming. Im gonna post new photos of the evolution of this so you get an idea of how it progresses.

October 31st 2016. Just finished blooming. You can see a spot on the flower stem and minor spots on the most recent leaf and a new leaf is growing.
20161031_081507.jpg - Google Drive

January 3rd 2017, spots progresses on the newer leaf as well as the one before seen in the top left corner.
20170103_083820.jpg - Google Drive

January 6th 2017, general view shoes progression of spots on leafs. The newest leaf is now full grown and you can see one small spot in the middle.
20170106_213312.jpg - Google Drive

February 20th, you can see progression of spots on leafs and stem. Started noticing the spots now have small brownish dots.
20170220_074811.jpg - Google Drive

Newer leaf is now pitting.
20170220_074824.jpg - Google Drive

March 4th,
https://drive.google.com/file/d/0B3I...w?usp=drivesdk

March 26th
https://drive.google.com/file/d/0B3I...w?usp=drivesdk

Today April 18th. Spots progressed on all leafs including the last leaf that is fully grown. The newest one that is still growing is still all nice, for now.
https://drive.google.com/file/d/0B3I...ivesdk-tmp.jpg

https://drive.google.com/file/d/0B3I...w?usp=drivesdk

20170418_081554.jpg - Google Drive


---------- Post added at 12:28 PM ---------- Previous post was at 12:14 PM ----------

I tried to imbed the images but it failed. I removed the (IMG) to show the url to avoid to have to copy paste the URL. If anyone knows of a site/service that is compatible with this forum please let me know thanks :-)

I think there is a problem between Google Drive images and the software OB runs on. I'm unable to right-click (long-click, actually) on the links on my Android phone, though I can see the URLs as I type this.