too cool, that you captured that on video!
The tachnid fly is a different hornworm parasite. The one I have is the braconid wasp. I think even if you never saw the predator, you would know because it doesn't look like this one would make the white cocoons we recognize as braconid parasitization.
This fly looks like a really nice one to have in your garden, because it is a generalist: Parasites of caterpillars (corn earworm, imported cabbage worm, cabbage looper, cutworms, armyworms),
stink bug, squash bug nymphs, beetle and fly larvae, some true bugs, and beetles. Adults are 1/3 to 1/2 inch long. White eggs are deposited on foliage or on the body of the host (in the picture below, the tachinid fly is approaching the larvae of an elm leaf beetle). Larvae are internal parasites, feeding within the body of the host, sucking its body fluids to the point the pest dies.
Note that even attacks the stinkbugs and squash bugs we hate!
It looks like the adult flies are attracted to the same kind of flowers as other beneficial insects, the ones that have nectar in tiny florets:
Anthemis tinctoria Golden marguerite
Fagopyrum esculentum Buckwheat
Melissa officinalis Lemon balm
Mentha pulegium Pennyroyal
Petroselinum crispum Parsley
Phacelia tanacetifolia Phacelia
Tanacetum vulgare Tansy
Thymus serpyllum coccineus Crimson thyme
https://www.farmerfred.com/plants_that_a ... enefi.html
so hopefully I have some of these flies around, even though I wasn't aware of it. I grow lots of lemon balm and parsley, some tansy, thyme, buckwheat, and other things in the same family as parsley.