You could try garlic in the soil. I first wrote about it here: http://www.globalgarden.com/Chile-Heads/Archives/vol.200204/0610.html It is supposed to kill all insects, good or bad. I'm not sure how well it works. The times I've tried it I don't think I had an insect problem to begin with. If your plants are in your living space you will smell the garlic. It's not a problem for me as my over wintered plants go under artificial light down in the dungeon, and I like the smell of garlic.