Way back when I delivered mail (a thousand years ago) I would run across a bee/hornet/wasp what ever, that measured 2 1/2 inches long and very thin and dig large holes in the ground.
The only thing I found close is this, Cicada Killer Wasp;
[youtube=425,350]http://www.youtube.com/watch?feature=fvwp&v=tomdi65QPxs&NR=1[/youtube]