sick phrag. Fritz Schomburg

[inbar]

Hallo everyone,
I hope that someone can help me with this.
My phrag is sick but I cant identify the problem. I don't see any bugs flying around it.
The leaves have a brown "rash" on the upper surface and the flower spike withered.
Does anyone know what it is and what can I do? Is it contagious ? Do I need to keep it away from the other orchids?
Thanks ahead!

 

[gonewild]

The photo detail is not sharp enough but it looks like mites to me. Have you looked it with a magnifying glass?

 

[big923cattleya]

Mites are so incredibly tiny and breed like crazy. Not sure if you can even see them. Their damage leaves hundreds, even thousands of tiny marks on the surface of the leaves. Sometimes a bacterial or fungal disease will enter these tiny marks which cause discoloration.
Some mites attack to top surface of a leaf, some attack on the underside. Some type of spray, a miticide should help. You will need a few sprayings to get them under control.
Increased humidity helps to keep them under control. I grow under lights with a humidity range of 50-90%. I don’t have mites. They prefer low humidity levels.

 

[kman]

I can't say if this is or is not mute damage, but I can share something I used to do when growing Salvias for sale.

If we had a valuable plant that had mites, we would hold it upside down with all the foliage in a bucket of water. In two minutes most if not all the live mites and a large percentage of the crawlers were killed. Now there were still live eggs and some crawlers, so this was not a 100% one and out cure. But it did knock them back enough than chemical control could be effective and halted immediate damage. Easy with a few plants. A quick way to get started with any control program. In any case its best to knock them out hard as half-hearted attempts never work well. Clear them out once and for all. It a particular plant was hard hit and not something rare or of breeding value it would be quickly removed from the growing area and trashed.

Growing orchids at 70 to 90% humidity I rarely if ever see a mite.