Wow, that's an ugly sight. How many vines do you have? Any chance of hand removing on a regular basis? I found this resource:

http://ipm.ucdavis.edu/PMG/r302301011.html

"Larvae have conspicuous tufts of long black poisonous spines that cause skin welts on field workers."

YIKES!

Yeah, I was reading that. Gross.
My boys and I donned some gardening gloves and threw them all in soapy water. I've sprayed the vines with neem oil so we'll see if I get any new attacks. Of all the infested leaves we only found one soon-to-be chrysalis. So hopefully no new moths are flying around looking to lay their eggs.

There are two vines in all and for some reason the critters like the Concord but not the Thompson. Interesting.

Bt?

I don't know what "bt?" means.

Bacillus thuringiensis, it's a soil bacteria that can be used as a biological insecticide. There are lots of commercial products available with it.

When I had an infestation they attacked only 1/4 all different species.

I'm with kentc. Bacillus thuringiensis is organic. Neem could work too. Neem with mess with the reproductive cycle. BT will kill all caterpiller type larvae.

Does BT have side effects for other plant life or helpful insects (bees)?

How is it applied to the soil?
Do you need to apply it before infestations?

I wonder if it would work on my bagrada problem in my kale and cabbage, etc.

I spray it on the leaves of grapes and tomatoes, and only use as a drench to kill larvae of fungus gnats. I don't have a bottle handy to read the FAQ, but you might find it on the internet somewhere. Google is your friend.