When I bring my plants indoors for the winter I put them into a room and throw a couple bug bombs in with them keeping the door closed with a towel at the bottom crack. I leave them in the room for the entire day, wait another week and do it again for any eggs that might have been laid in the dirt. Throw another bug bomb in with them. Seems to kill most of the bugs and their larva. I'll have a few bugs that get past this procedure but not many. My sister uses some garden chemical that starts with an "M", pours it into the pots till it pours out the bottom. Something called like myathane, spelling not correct.