Asian predatory wasp

Yes that very well fits, thanks Marco

It's Vespa velutina

After searching for hours now - what you think about Polistes sp.?

the nest is a honeybee nest....the wasp (?) was preying on the bees

hmmm, I looked it up....looks somehow different Joe

Is that a large papery-like nest, like a big balloon, in the picture on the left? If so, this may be some type of hornet.

this one was about 3 cm...but i have seen a little bigger ones before

Looks like a cicada killer. It would help to know size as they are rather large around 4 centimeters long.