These are real beasts to get rid of. Try spraying in the evening when they are home for the night too. The problems is the little buggers fly off when you spray. I had these one winter from fuchsias from a commercial greenhouse. That summer when nothing was in the greenhouse I bought a greenhouse bomb and washed the whole thing down with bleach water. I'm very picky about what goes in there but it's only 6 x 8, so nothing like you have.
