This is a new variety of "paper wasp" (polistes f____, IIRC, maybe "German ___") in my DC area awareness. Its coloration is just like a yellowjacket's, and to some degree so to are its nesting & hunting habits : i.e., I've seen them scavenge (in contrast to the familiar species' hunting specifically caterpillars) --had one alight on my hand and while the other hand reached for the LX3 to photo, she "wanted a piece of me" and bit me (!) (ouch, I didn't like that pose ; no photo); and these tend to nest IN something --such as automobile side-view mirror housings, or between street sign & V-shaped sign post.
With an LX3, I've gotten pretty close (its macro feature is closest at wide end (24mm equiv), but one needs to be careful not to scare them.
Given 300mm (equiv. 450) and assuming no cropping, my guess for this is perhaps a metre?
