White flies are actually a bright white in color and are not in the dirt. Fungus gnats are what you are dealing with. They have a 6 day life cycle and eggs are in the dirt. They are hard to get rid of. Overwatering is the main culprit. Keep soil drier. Christmas Cactus' like it better that way, anyway. The yellow sticky cards that you can buy work really well for indoor infestations. If all else fails, I had to take a plant out of the dirt, rinse it's roots and put it in new dirt once. The old dirt should be pitched or you can bake it in your oven to kill any eggs, etc.
White flies are actually a bright white in color and are not in the dirt. Fungus gnats are what you are dealing with. They have a 6 day life cycle and eggs are in the dirt. They are hard to get rid of. Overwatering is the main culprit. Keep soil drier. Christmas Cactus' like it better that way, anyway. The yellow sticky cards that you can buy work really well for indoor infestations. If all else fails, I had to take a plant out of the dirt, rinse it's roots and put it in new dirt once. The old dirt should be pitched or you can bake it in your oven to kill any eggs, etc.