I'm not a Polistes expert, but this looks P*metricus, or even more so, P*parametricus to me. Placement here needs to be justified.

As for the prey, rather hard to see, but I'm leaning toward something dipterous, maybe a crane fly.

Prey mainly on caterpillars or other eruciform larvae, they do sometimes kill winged insect like this Dipteran fly, provided these are not quick enough to avoid capture.
Your pics are interesting in their own right by showing the EXTREME darkness of at least some Maine representatives of Polistes fuscatus.

This is indeed P. fuscatus, I've never seen one this dark though!!

Paper wasps usually hunt for caterpillars/soft bodied insects for their young, but anything that suits their needs is a possibility for a food source.

Adults mostly feed on nectar, some of the juices from the malaxated (chewed) prey for their larvae, regurgitations from nestmates, and larval saliva (known as larva-adult trophallaxis, the larvae secrete drops of saliva which the wasps eat).