I do not have any images in my wasp folder that look like this guy. Looking through the guide, I see both Chalybion and Chlorion genus as possibilities, though it is probably something else altogether. It was making short hops through mown grass and I saw it fly into a spiderweb. I did not see it capture anything in the web; I don't know if going into the web was prey seeking behavior or just an accident. It had no difficulty extricating itself from the web, though.