Enaphalodes sp. (Oak Borer).
Size: approx. 25 mm. Photo: 08/22/15, 9 pm.

This Oak Borer is either Enaphalodes atomarius or E. cortiphagus. Quoting from the second link: "All species of Enaphalodes are nocturnal and strongly attracted to lights; adults emerge from hosts at night from April-October in the United States and do a little feeding on twigs and foliage. They aggregate on sapflows and can be collected with fermented solutions." 
bug guide (this photo):
Lingafelter & Chemsak, Col. Bull. 56, 569, 2002: