Orchid collection dying

[tylerumn]

Hello everyone,

I'm fairly new to collecting orchids and as such, have never experienced an orchid dying from pest or disease. Right now, 80% of my orchid collection is dying from what I can only describe as "rust matter" settling on the leaves of my catts., dend. and paphs. I attach a picture of two different catts. that I have with the entire plant as well as a close up.

I noticed the problem started to occur early this fall; the "rust matter" was very small on a single leaf and I ignored it. Now it's covering my entire collection.

Could someone please give me a diagnosis and recommend a treatment?

- tylerumn