Similar thing happened to me on a rather busy road. Wasp flew into my jersey (thwack! then the stinging commenced). I hastily un-clipped and threw my bike in the ditch then danced around trying to get it out. Had to resort to stripping down to my bra on the side of the road!!! I'm pretty sure I looked like a complete whack-job...half-naked, jumping up and down and flailing wildy. Lucky I didn't get arrested!