Because it bores into wood, I think it has to be some type of carpenter bee. When I googled blue black bee, I got references to mud wasps and carpenter bees. It looks similar to a Scolid wasp with blue wings but I could find nothing about Scolid wasps drilling holes into wood.
I think poster is on the right track. I'm way out of my realm here, but the solitary wasps in the genus Isodontia often use abandoned carpenter bee holes as their nesting sites and they bring pieces of dried grasses to the nesting sites. My guess is Isodontia philadelphica. Here's a link:http://www.discoverlife.org/20/q?search=Isodontia+philadelphica