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.

[![hibiscus mites](https://i.stack.imgur.com/7FKCK.jpg)](https://i.stack.imgur.com/7FKCK.jpg)

Any ideas on what they're called or how to kill them completely?