bgian,

This site can only give you a basis for comparison,

http://www.users.on.net/~gmcorbin/BOS/virus.html

but if you are interested in having your orchid tested for virus, the following linked U.S. lab has been recommended on this forum.

The usual sanitary precautions to prevent spread of a possible disease are in order.

Sweetcicely

Here is a link that might be useful: Testing lab

Nah, not a virus. You've got mites :(

Someone has a mites/phal post going now, so you should check in there for details. But you need to wipe down all of the leaves with something as simple as soapy water, but you should do this 1X/week for 2-3 weeks. There are safe miticides out there too, but this is where I recommend that you do a search in the forum to get the all of the details.

Carolyn

It's good to know it isn't a virus or other disease. At least there are treatments for spider mites.

Carolyn ~ It would be very helpful if you could share the signal points in bgian's pictures that told you that mites were the culprits, so that I might be able to recognize them "next time."

Thank you!
Sweetcicely

Hi there!
I have less than a year's experience with orchid culture, but I sure know lots about spider mites lol!
They are crafty little devils and don't advertise their presence- they hide in the potting medium. If you do happen to see them, you couldn't imagine that those barely visible moving black dots could cause such havoc!
So, they attack lower leaves first, as those are nearest to where they live. They chew ( or suck out the juice from) the edges of the leaves, causing discoloration or irregularities in the leaf edge (black marks at top of photo). Next they suck the juice from the tips of the leaves, causing the yellow discoloration. These parts of the leaf become thinner and almost translucent. There are sometimes brownish streaks on the underside of the leaf. If left to their own device, the mites will produce a thin web between the lowest leaf and the top of the medium.
Since I have started cleaning the leaves with warm soapy water once a week, (and pouring the remaining mixture through the medium as suggested by Stitz in a recent thread) I think I have the problem under control. I may not have eradicated the pests entirely, but my orchids are healthier and certainly look a lot better.
Good luck!
Judy

Have you sprayed them with anything in awhile?
I have some that look similar except they are worse...And yes the new leaf is perfect. I thought mine might have been virus but have tested for that. It is from Fruit/Tree spray that I treated plants with in the fall for bugs. Not one phal escaped it. They don't like it so I won't do that again. Good luck gb

Sweetcicely (and all),

I know it's mites becasue I have recently had to research them myself :( Just like Judy.

The 1st, biggest giveaway is the roundish sunken dead areas. Typical mite damage. Those yellowish areas appear to be being attacked from behind, which is where mites love to hang out. (OP- any pics of the under side of the leaves?)

Since you can't easily see mites, only their damage, a tried and true test (although I can't say that I see it) is to take a tissue, swab, cotton ball, etc, dampen it (H2O, or I use alcohol) and wipe the underside of the leaf. If you come up with a reddish tinge, you've got mites. But, since I don't really see anything when I do it, I just know what the damage looks like. If you google spider mites or mite damage, you should find pics.

Also, orchid viruses are supposedly more or less uncommon. Most hobby growers have insect or fungal/bacterial damage if there's a problem, rather than viral, unless you happen to get an infected plant (again, more uncommon).

But, after you've looked at enough pictures of both mites vs virus, you get an eye for what mite damage looks like. here's a discussion of this topic from this forum
http://forums2.gardenweb.com/forums/load/orchids/msg0710185229356.html

Here's some other picts
http://www.ionopsis.com/Pests_and_Diseases.html
http://forums2.gardenweb.com/forums/load/orchids/msg011644515336.html
http://www.users.on.net/~gmcorbin/BOS/virus.html

I'm no expert, but this just screams mite damage to me.

Carolyn

recently, i have used scotch tape to take off scales and spider mites off some leaves and it seems to work really well. i had to go over the same spot about three times with clean piece of tape each time. there was no damage to the leaves from the tape. i find that when i wipe the leaves with soapy water or whatever, i always drop some bugs into the medium. with the tape that does not appear to happen. but then they are so small, i am not 100% sure. anyways, i used the tape about 2 weeks ago and so far everything looks fine.
sue

Bgian, I hope you are still here, reading all the good information above.

Judy (savtaj), you have my condolences for your long experience with these critters! Thank you for the eye witness and control tips.

Carolyn, thank you for the first thread discussing orchid viruses--it was before my introduction to the orchid forum and very helpful. I remember the thread (3rd url) regarding leaf streak virus, which infected my domestic ginger (Zingiber officinalis). I guess when one has seen one of these viruses they don't seem so uncommon.

It was the similarity of Bgian's leaf symptoms to the second picture on the Brisbane site (your 4th url), saved from another virus discussion, that caused me to think the problem might be ring spot virus. But, then, the old saying applies: "When you hear hoofbeats, think 'horses,' not zebras." :) Having no experience with spider mites on orchids, my first thought was viruses (zebras).

Your second url (ionopsis site) goes to the best overview I have seen on orchid pests and diseases. Thank you for sharing all your good information on recognizing mites. I've learned a lot.

Sweetcicely

Sweetcicely, you're so gracious, and well, sweet.

happy to help anytime :)

and if anyone else thinks virus, please speak up, because I'm new to diseases except for scale, and so just because my hoofbeats have been from mites, that doesn't mean that there aren't zebras lurking in the jungle.

Carolyn

Nah, I'm with you Carolyn, looks like mites. I've never found the reddish tinge either.

Sue, they are in the medium. I use a organic soap spray or alcohol.

Like scale, they always reappear. You just have to stay on top of them. They like Dens too.

Jane

Thank you very much!!! This is a big help! Is there any particular type of soap I should use??? Also, I have an oncidium that looks a little yellowish, but doesn't have those particular spots. Could that be mite damage too?? Thanks a bunch everyone!!!!

You could use Murphy's Oil soap. I use it on my succulents too.