Oil beetle w/ parasites?

When I first saw this insect, I didn't know what it was -- but I thought maybe it was a female carrying a few of her young. Upon further research, I now know this is a male oil beetle, a type of blister beetle. But I cannot figure out what the beetles are on its back. Any thoughts or ID on them?

I will update this spotting with other photos, info, and a video later, but right now I'm trying to find out more about the parasites.