This actually happened a couple weeks ago. Shortly after it flowered, something completely devoured the leaves on my yellow loosestrife (possibly the flowers too, not sure). I don't think the plants are dead, but they've taken serious damage for sure this year. By the time I noticed the damage, the insects had already left and went somewhere else (or maybe I just didn't see them). Whatever it was they did their damage very quickly and moved on. Anyone have any ideas as to what this might be? What insects have you seen eating your lysimachia punctata in the past?