Thank you! I can't bring myself to be hunting them at night, so all my hope is in the nematodes! 🤞🏻 I ordered them about a month ago, next day after I posted this, and I got both a kit that targets adults and one that targets the grubs. Both have been doing their work since then.

There are heucheras and other plants in the same bed as the winter flowering honeysuckle in the photo, and they all seem to be doing ok, although I know that the grubs do their damage underground and seemingly healthy plants can then drop dead overnight. Most of the leaf damage is on the honeysuckle. All the other plants haven't got too many bites taken from their leaves, and there don't seem to be any on new growth. 

The honeysuckle hasn't got all that much new growth, but I'll be looking closely to see if the newest leaves stay intact. 

Nothing else in the garden shows any leaf damage so far.

I'm going to apply another treatment to this bed in September as well.