How to tell good grubs from bad?
As I've been preparing my beds, I keep digging up little grubs of various thicknesses and colors. I've been killing them, figuring that for all I know they're Japanese beetles or other garden pests, but it seems to me that some might be beneficial Â for example, ground beetles are supposed to be slug-eaters.
Actually, I've only found about a dozen, so my efforts probably aren't making much difference either way.
So how do I tell which to kill and which to keep?