So the question now is: What gets rid of them?
Find the hottest pepper you can purchase, boil it, drain through a sifter. Place the liquid contents in a spray bottle and, apply to plants.
Vanilla and peppermint will do the same thing.
Soap and water is the answer. Soap (like Dawn dish soap) is an emulsifier, ie. it cuts grease. Bugs are exoskeletal (bones on the outside) and the emulsifier allows oil to mix with water. So, the oils lubricating their joints goes away and the bug dies. I know people who wash their cats and dogs in Dawn to kill fleas.