Whats this

[orchid nut]

These pictures from a Cattleya lueddemanniana, anyone know what these spots are. I've treated the plant with Phyton 27 and Orathene but I have no idea what this is ?

[articuno75]

I'm sorry, but these look to have a virus of some sort. Maybe TMV? (Tobacco Mosaic Virus?) Truthfully they need to be destroyed. Wait and see for more opinions first.

[Cynthia, Prescott, AZ]

I don't think it is virus, but it might not hurt to check. My guess is a fungal infection. Have you been using neem oil in the last few months? You might want to look at this picture of a plant that came back negative for virus after a green house screening which we deemed insufficiently accurate, and again negative after a double well test, so I am pretty sure this symptom, some what similar to yours, was not virus. What seems particularly telling is the dot in the center of the pattern on your plant, like a beginning of an infection, with the infection then spreading outward.
Test was negative for CMV, ORSV, & BYMV in Laelia perinii photo - Admiral Schnitz photos at pbase.com
And more interesting non-viral problems.
Symptoms NOT caused by virus Photo Gallery by Admiral Schnitz at pbase.com

[orchid nut]

I quit using neem oil about a year ago, every time I used it something came up dead not to mention it gummed up my sprayer. The picture you added is the closest I've seen to my plant, I think I'll separate it from the herd and keep an eye on it for a while, I would like to bloom it before I destroy it.

Thanks Cynthia

[Cynthia, Prescott, AZ]

You may want to look for one of the many brands of Thiophanate Methyl to have for this plant, and as a preventative spray for the rest of your plants just on general principles. This stuff and the Phyton 27 have different fungal bad guys that they work on, and between them, they probably cover most everything, and are both systemic. The Thiophanate Methyl is sold as OHP6672, Cleary's3336, Bonomyl, Fertilome Halt, etc. I certainly would spray the rest of your collection occasionally with the Phyton just in case.

[articuno75]

Here is a website that has some pics of virused plants that look similar to what yours looks like. I have some other pics of similar spots and streaks. Virus Diseases

[Cynthia, Prescott, AZ]

I don't doubt that these are virused plants, but I find it interesting that I have never seen these symptoms on my 100 or so positive reacting plants to one of the immunoassay tests for common orchid viruses, with the possible exception of a couple of Cymbidiums that I have yet to have tested for virus, but suspect to have virus. It would be very interesting if the OP would have the plant tested. The place I have mine tested is Critter Creek Labs. Critter Creek Laboratory

If you decide to have it tested, ON, spend the extra dollar for the double screening test, it is much more accurate.

[orchid nut]

I have probably 500 orchids growing outside we live in South Florida and I have lots of plants with strange looking marks I'm not about to just start trashing plants for what could very well be an environmental issue .I've sent a sample to critter Creek we will let you know.

[orchid nut]

The results from critter creek were negative for cymMv and orsv I guess that leaves some 40 other viruses. I would destroy the plant anyway but its a clone of a rare plant Leuddemaniana semi alba aquinada ' cerro verde' am/aos.

[patticake]

Wow- Thanks Cynthia & Jenny- for some great info. on some nasty stuff. Hope all goes well, orchid nut. 500 plants.... oh, to live where it's warmer!

[Cynthia, Prescott, AZ]

Well that is good news, and is an eye opener with so badly marked a plant. My guess is a fungal problem is the cause, as I also suspected with the plant that you noted was the closest to your symptoms. I have also seen some patterns like these on leaves that were being cast off by the plant, and no longer being supported in a manor that would resist fungal infections. Need to put that picture on my site. I am sure this plant will out grow those marks, so just hang on to it. I would like to put your picture onto my pbase site if I may. If you are willing pm me to let me know, and I will send you a pm with my email address to send a good full sized picture.

[orchid nut]

One thing I have learned you must practice sterile techniques and you need to isolate suspicious plants. I have a place on one of my benches where these go I call it deaths doorstep.

[digitalgate]

orchid nut why would you want to throw away? They spread mainly by cutting tools (may b
insect too). I have dendrobium that spend years with me and have not spread to the rest
of the plant. Of course it is used to cross hubrid as seed pod does not spread virus.

[Cynthia, Prescott, AZ]

I have what I call my bone yard for virused plants, as they are not expected to return.

[Cynthia, Prescott, AZ]

OK, my pbase site has been updated with Don's pictures and a few more of mine.
Symptoms NOT caused by virus Photo Gallery by Admiral Schnitz at pbase.com