This wasp was digging a whole and carrying balls of sandy soil away.
Podalonia sp. Wasp (Sphecidae), New Chicago Marsh, Santa Clara County, California - August 1, 2009.
Thanks to E. Eaton for correcting my initial misguided ID and providing a genus for this wasp.
Sphecidae (Latreille, 1802) is a cosmopolitan family of wasps that include digger wasps, mud daubers and other familiar types that all fall under the category of thread-waisted wasps. Both of the traditional definitions of the Sphecidae (the conservative one, where all the sphecoid wasps other than ampulicids and heterogynaids were in a single large family, and the more refined one, where the 7 large sphecid subfamilies were each elevated to family rank) have recently been shown...
