Here are some close-ups of them. They're a bit dried out.

I stuck it in a cup, and the flies stayed right there on the caterpillar, although they moved around a bit. I was in a hurry to leave, so I just put it aside and ignored it for a while. I figured in a couple of weeks I'd either have a butterfly to release, or a cup of flies.

I got the cup of flies.

You can see a lot of them got stuck to the tape. I finally opened up the cup to photograph them today. I counted 81, but I could have missed a few in the folds of the tape.

I snapped the pictures, hoped there was at least one good photo, and came to the pc to make this page. Now that I'm sitting here looking at the close-up images, I think these might be wasps, and not flies. Someone who knows for sure, please send me an email, and I'll post your ID here. Whatever they are, they ate my caterpillar!

I did catch one bug that I know is a parasitic wasp.  See it here.