Location: Indiana, USA
Every spring, carpenter bees make a few holes in our exposed porch wood. This year, we observed a woodpecker removing three 1+ cm white grubs from one of the holes after a week or two (this hole is on the underside of a porch rail). Interesting enough. But now, I observed some kind of wasp carrying plant fibers into the same hole, so I guess it is using it as a nest. Here's a picture of the wasp, and also of the wasp disappearing into the hole with large green piece of grass (at least it looks like grass - definitely a strong flyer). The hole is about 8 mm across, and the wasp body about 1.5 cm. Anyone know the species of this wasp?
Update: Here is the apparently completed nest: