
Yipes! They were three inches plus a four inch ovipositor. I sent the pix off to a few friends as well as the bug guys at Clemson. It turns out that the bugs were giant female wasps that were laying eggs in the wood to kill other wood eating larvae. I've got an entire predatory ecosystem in the yard.
It's a bug eat bug world out there...
qv: Phil's Gallery of Bugs at Flickr