Hi, JoJoe, Just finding this thread late and was wondering if Lorimar's post was what you had.
I have a lot of rhipsalis and generally do not see much in the way of scale infections. It is, however, common to get some tan/gray areas on some stems of some varieties. Not sure what causes it, but it does seem to be related to misting or not having the plants exposed to rain to flush away buildup of crud. My first reaction was in agreement that you had some sunburn.
Post back or dmail me for followup. Do you have better pics at this point?
