That sounds like a root-boring bettle. Those are very bad. Can you post a picture? Probably tiny I imagine... try a neem solution mixed with Organic S laundry soap from Walmart as a starting point. Most biting/sucking things don't like that too much.

Hi, Sundewd. I'm not much of a photographer, otherwise I'd post a picture for you.

These don't appear to be borers. The leaves are bitten into, like Cookie Monster taking a big bite of cookie. :D But no signs that anything is sucking the plant (no yellowing) or boring into the thick central roots of the larger sedums. (I carefully pulled up a couple to check for this, then replaced them.)

One nursery employee suggested flea beetles, but these look too big to be that type, and too small to be the Borers you mention (unless mine are still juveniles...? I also don't notice many grubs in the ground nearby. I work that soil fairly frequently pulling weeds and such, so I feel like I'd notice if they were there.

One other possible culprit is caterpillars. I'll check in with a local extension service tomorrow and see what they have to say. I hate using poisons, but I'd also hate to lose my sedums. In my rock-heavy yard they're a real godsend.

[sigh] Well, the Extension Service wasn't much help. I'll leave it at that.

On Saturday, I bagged up some of the offending beetles right on the plant and took them to a nursery. They recommended Spinosad, with a caution not to spray it on while the bees are about.

I hope it works. My poor hens-and-chicks are really taking a beating, and this is a spot where it's very hard to get other plants to grow. DX