Did you try diatomaceous earth? I use it in garden for bad bugs.
Diatomaceous earth is great stuff. I've used it for crickets and ants. It's reputed to also be effective on earwigs, cockroaches, and all kinds of other harmful insects. Does the same thing to the exoskeleton that a spike strip does to a car's tires.
Cute, huh? The little buggers are called Sri Lanka weevils, and they're smaller than my fingernail. Best I can do is pick them off the plants when I see them, and stomp them to death. When I do so, I imagine they are dwarf derps. ;-)