They are weevils, a type of beetle. They typically make notches on leaf edges, but given just one plant to eat, they may destroy entire leaves. I would think a few nights of keeping after them would reduce the population to zero. Weevils do hang out in soil at the base of plants. Often they will notch the leaves of one plant while adjacent plants remain uneaten. Perhaps you have seen such notched plants in your yard.

Thanks Larry, it sounds like the weevils will be a pretty easy problem to solve (if it's not solved already)

I never imagined there could be garden pests in Minnesota...in February!

One more question about weevils...are the garden variety usually bigger than the kind found in home? These little suckers were easily 3/4" long. Or were they just extra "fat and happy" from the butterfly bush?

There are many species of weevils, they can very greatly in size. Your all-black weevil looks similar to the ones common around here that may be 3/4" long if you include the antennae.

The size of the adult weevil would depend on how "fat and happy" it was in the grub stage, not on what it was eating as an adult.

In the outdoor garden, many people apply sticky tape or substances to the base of the plant that prevent the weevil from ascending.