The purple passion photo looks more like the "brown crusties" I am familiar with. Except that the photo shows a really bad infestation. Usually with episcias this crud is confined to the smaller new growth before we go ballistic and haul out the spray. But, that is the general effect of cyclamen mites. It starts in the tiny new growth and then spreads to older leaves. So, when I have a plant that has some bad leaves and I don't know why, I instinctively look at the new growth to see if it looks mitish (new word!). If I suspect mites on just one plant I can put it in isolation by enclosing it in a ziplock. If it is mites, the high humidity won't kill it and I will know soon enough). If the condition is from some other source then the plant will grow out of it. But, plants never grow out of cyclamen mites until they are treated. People say that mites are very hard to see with magnification. So, I wonder if they reproduce into thousands and do their damage or if the same few bugs get in under the surface of the growing tips and do all the damage. It doesn't matter really to know this.

Jon, your friend in the mite garden, so to speak....

Fingers crossed, salt over the shoulder, knock wood, I've not had to deal with any pests except thrip. It is my personal opinion that thrip only live on plants with dark blossoms. So, if you avoid those, you won't have thrip (tongue throughly in cheek).

Almost time to go teach dog school.....

Linda