Strange spots on Phal leaves

[Sarah_bee]

Good morning everyone. I posted something last week about having an issue with the leaves on some of my phalaenopsis. I have started noticing these very strange looking dots on the leaves. It seems to be pretty wide spread. There are no signs of insects at all on any of the plants. I am stumped. From the top of the leaf it looks like it is losing pigment in some areas and when you lift it to the light and look underneath you can see a definite yellow spot with a dark dot in the center. Should I throw them away? Treat them? This does NOT look good.

[silken]

It's definitely something not good! Are the dots raised bumps? I can't see enough detail in the photo, but if so, it could be scale, sucking the pigment from the leaves. Scrape lightly and they come off. I've never quite seen that kind of damage from them before. If it is scale, you need to segregate these plants from others and begin treating it.

[Sarah_bee]

The spots, even the dark speck in the center of the spot, all appear to be part of the leaf. The yellow spots and their dark centers are only really visible when held up and light is shining through the leaf. it looks like the black speck has a yellow halo or something.

[silken]

Hopefully someone else will have some thoughts. I would still isolate them as it sounds like it could be a fungal or bacterial infection. Have you tried wiping the leaves with a damp white tissue to see if any pests come away such as spider mites, which are hard to see with the naked eye?

[Sarah_bee]

yes, that was one of my very first thoughts when I started to see the discoloration on the leaves (spider mites) but there is no evidence of any sort of pest what so ever. I almost wish it was at this point! (I don't really mean that, but I kind of do!)

[Leafmite]

I hope you find the answer! I am sorry that I cannot help you. Good luck!

[Sarah_bee]

A more detailed description:
The spots are only visible on the underside of the leaf when light is coming in from the top, almost like they are watery spots or "clear" but the spots do not feel watery and are not seeping any fluid. They are about 1cm across. The speck in the center of every dot is black or very dark brown (appears black) and no bigger than the head of a pin. Tiny. The cells don't appear to have collapsed, there is no depressed area in or around the spot. From the top of the leaf the spots appear to only be a slight yellowing in the leaf with no distinct outline.

[silken]

I would probably prefer an insect problem too. At least it is an obvious thing that you can deal with. If you have a fungicide/bactericide spray, I would probably treat them. Hopefully someone can come up with a more definitive solution for you. Google St. Augustine Orchid Society and they have a great website with pictures and treatment options of many pest problems including symptoms of fungal, bacterial and virus problems.

[Sarah_bee]

I have been all over that website! And any other that I can find. The only thing I have found at all that comes close is this

http://www.orchidboard.com/community...sis-leave.html

I sprayed with Phyton 27 and Subdue about 10 days ago.

[silken]

So they were also like this 10 days ago? Has it gotten any worse or spread to other plants? The other person's leaves did look much the same only maybe not as bad. Maybe you should ask them what the end result was.