If you are having trouble with Japanese Beetles, plant marigolds around your garden... or around the area where you have basil. Japanese Beetles are attracted to marigolds and will usually go there first...
Also the simple bag traps that have a natural scent hung in the area may help too... I am not sure about these, but I do here that they have them without chemicals.
I hear you about spraying! I would not spray my basil either. It just doesn't sit right with me...
Good luck!
