Thanks for calming my nerves, all! We did decide to spray the big cluster of them on the one hibiscus, and the stragglers eventually left just as mysteriously as they came. They must have all just hatched, and then moved on.
I'd be curious to know how you tell them apart from the milkweed bugs too, just for my general knowledge! Glad they didn't pose a threat to anything in the flower bed, just creepy and definitely crawly
