catasetum with leaf spots

[shahnw]

My catasetum has recently developed these chlorotic spots. In a few places, there appear to be larger, irregularly shaped black spots, the largest of which is slightly translucent at the center. I have a second catasetum that has also started to display one or two of the small spots. I have thought thrips, spider mites, and cercospora, but I am fairly ignorant in this area and at a loss for what it is and what to do.