thanks for the lead, i did some more reading and found this article in a scientific journal about its natural predators in Turkey. so hoverflies, lacewings, ladybugs (which i saw on the bushes too) and other beetles eat the larvae.

there are still too many tho so i might gather some into a terrarium and try and trick them into pupating and emerging in the winter. i think they become really pretty small black wasps, so i'll take photos with a magnifying glass, let them live happily and die of old age, then leave any eggs to freeze outside or sum.