A while back a store bought sunflower was absolutely covered in little green larva looking things. I left it outside but they appear to have migrated to my hibiscus. I've been spraying it with a water + soap + rubbing alcohol solution. None of these mites seem to be alive and I see no movement, but they still seem to multiplying around new leaves. They leave a flaky yellow crumb looking sluff behind, have small green larva and adults seem to be the brown guys in this picture.
Any ideas on what they're called or how to kill them completely?