The best clue to virus is what is called a color break. This is a smear of lighter color on a flower.

There are so many things that can happen to leaves that virus is way down on the list. A trained eye can sometimes see the mosaic virus on leaves, but it is generally not the cause of leaf problems.

Got a picture?

Color break on the flowers of most, color break on the leaves of Cymbidiums, necrotic spots on the leaves of Cattleyas.

Nick

Is there an easy way to tell if my orchids have a virus???

Yes, test.

You can do it yourself, as I do. I use a product sold by Agdia. info url:
https://orders.agdia.com/Documents/m250.pdf

You can also pay a professional to test for you. On occasion, I do this also. Critter Creek Laboratory is well known for these services. info url:
http://www.crittercreeklab.com/

You cannot "look" at suspicious tissues and make an accurate determination of viral health status. You can guess!

Laboratory testing, whether done using an at-home kit or in a professional setting, is not "fool-proof". The results are considered more than 90% accurate.

Good Luck!

--Stitz--

I have tested several Cattleyas with color breaks in their flowers and have never had one test negative when they showed this. Had the same 100% compliance when testing Cymbidiums with chlorophyll breaks in their leaves.

Has any one had negative tests on plants showing the above characteristics?

Nick

Nick, I have had cymbidiums with chlorophyll breaks on their leaves back negative from critter creek, as well as with agdia strips....the patterning looks incredibly suspicious though. No treatment of insecticides/fungicides/bactericides show improvement, and the plants seems to grow decently...I haven't read extensively about what/which epitopes the antibodies of the ELISA recognize, but the chances it's missing something is really low....who knows? Either way, plants were chucked...better safe than sorry.

{{gwi:194175}}
(see panel A, B...virusy?)

The markings in exhibit A are very similar to those on the leaves of two Standard Cymbidiums in my possession. One is a plant that used to belong to my son and has been in the family for at least 20 years and the other was a gift to the orchid society where i am treasurer.
Both plants are in bloom now and the flowers are perfect. Needless to say neither plant has been exhibited or sold.

Exhibit B is similar to the markings on the leaves of some Australian Native Dendrobiums. Maybe fungus scars.

Cannot comment on C but negative virus testing is interesting and ties up with the results at an orchid meeting when some really awful looking leaves tested negative by the gal demonstrating some virus testing kits.

Again a plea for calm a measured response if you see a suspect plant at a show or an orchid meeting. Do not run around telling all and sundry VIRUS as i have seen some awful things happen and as a result people were lost to the orchid growing hobby forever.

Just see the Show Marshall or whoever is in charge and ask them to take a discreet look.

Arthur,
Thank you for your sage advice.

--Stitz--

The photos above do not represent what I consider chlorophyll break. What I need to see is a longitudinal streaking along the length of the leaf. It is a lighter green and is not spotty but streaky and does not look at all like the 3 photos. I have only seen it on Cymbidiums and some long leafed Oncidiums but not on the Catt like plants.

What ever! The only thing that matters is a high degree of awareness and appropriate disposal of affected plants. All of us develop our own method of detection that we feel comfortable with.

I'm repeating myself but for me that is:

1) Color breaks on flowers of Catt like plants.
2) Chlorophyllum break on Cymb/Onc like plants.
3) Positive test on all others that I find suspicious and have tested.

Nick