psocoptera

as best as I can remember, the idea of depicting sacred/holy/special/powerful beings/people with something surrounding them is pretty ancient; Indian, Egyptian, Persian, although whether it's the kind of thing that multiple cultures came up with or whether there was a kind of ground zero I don't know. But using a mandorla (the giant almond-shaped full-body halo that shows up a lot in Byzantine Christian art and other early Christian stuff) is a pretty good way of setting the person in it off from the rest of the painting, kind of visually representing that they're in the world but also not in the world, etc etc. The head halo which developed much later is much less effective at just making that point without cultural context.