black pits on phal leaves

[BD11]

I noticed these black pit spots on one of my phal orchids. I have had it for several months and just noticed the damage.

Could this be spider mites? I looked the plant over and over last night and wiped the leaves with tissue paper. I never saw anything but could have easily missed the signs.

It has been sitting next to another oncidium orchid and a Chinese evergreen. Neither of those plants show any damage.

I don't have an prior experience with pests other than gnats that a lot of house plants get. So I was hoping someone had seen this before and could give me some advice.

I attached a picture of the leave in question, the whole plant and one of the other leaves for comparison.

thanks