Sounds like whiteflies to me . A mild insecticidal soap would do the trick . Take a damp paper towel and gently wipe off the leaves now that you have shaken the little buggers off . Another suggestion is lady beatles as a beneficial insect , but since they are inside you probably don't want to bring in more bugs . Before you bring them in at the end of the warm season get some lady beatles and let them do the job . On a warm day you can put the
plants outside and give a good blast from a water hose , or put in the kitchen sink and spray with sink sprayer . It will knock them off the
plant and not hurt it either . But do it early in the morning and that way the leaves have time to dry and not introduce fungus to the
plant .