Strange spots on Phal. leaf
 

Hi All,

I need some help with my phal. As you can see in the picture, the newest leaf on my NOID phal. has these small brown spots. They are sunken in, but not really wet or mushy. No pests except the odd mealy bug, and I've never seen them damage an orchid in this way. Also, I sprayed 9% hydrogen peroxide on the area about 2 days ago to stop rot spreading from the lower leaves. The spots appeared some time after that (but at least the rot isn't spreading :)). Could this be burn from the peroxide?

With regards to culture: Sunny location, warm, indoors, quick drying medium (bark). Little if any airflow, but all the other orchids seem fine in these conditions.

Thanks!

Small sucking insects, perhaps?

Hopefully others can chime in.

Probably Mesophyll Cell Collapse. It can be caused by cold water on the leaves. It's not a disease but a reaction to some environmental element. It is possible for bacteria to cause secondary infections in the spots but if that doesn't happen then the leaf will just stay like it is. It won't get worse and it won't get better.

Thank you, that makes sense. It is winter here, so I must have gotten some cold water on the newest leaf. At least it is not contagious :), since I don't really have quarantine space for a sick orchid right now.