Yeah, wasps really stink. Here in Houston (and much of the deep South), during the summer wasps are out in full force. They nest in every structure you can think of, including brush/trees. Apparently we've even got killer bees here now.
Anyway, I've been riding along at a nice clip several times and felt something hit me in the torso, only to feel a sharp stinging sensation over and over. After freaking out and jumping off my bike, ripping off my jersey, and generally jumping around like an idiot, I see the wasp fall/fly out of the jersey. Not a pleasant experience by any means.
I'd much rather get stung by a bee (in the above situation) since they can only sting once. Wasps will sting you repeatedly until it either dies or flies away. Ouch.