Mealy bugs, Annabelle. Isolate the plant immediately. Grab some Q-tips, soaked in rubbing alcohol, and gently rub those colonies of bugs off. If you even suspect that those mealy bugs are in the media zone, un-pot the plant so you can attack them everywhere you find them. After getting rid of everyone you find, rinse the plant with clear water. You won't get them all though. They will be in tiny nooks and crevices that hid them. Follow up in a week or so, doing the same thing with any you find. You might have to do this a third time. Just keep your eyes on the plant and keep it isolated.
Increase the air-movement around your plants. This is probably the most neglected of all the "Do's". The Susan Fender has a wonderful flower.