Yes this happened to me this weekend. I was almost exactly halfway through a 54-mile ride when I felt a bug crash into the side of my head between my helmet at sunglasses. I quickly tried to brush it away since it seemed to be stuck and making a lot of stressful-sounding bzzzing noises. I felt two sharp pinches, freaked out a bit more, started swerving my bike all over the luckily empty road, and finally freed the trespasser all while cursing intensely. I pulled into a driveway, and tried to assess the damage using the camera on my phone. Although painful, I luckily experienced no swelling of the area, and while ready to call for an emergency pick-up, I was totally okay. It was still a terrible experience, and of course as these things go, it happened when I was at the point in my ride that is farthest from home. I couldn't even take a short-cut since my route was nearly out-and-back. The salt in my sweat rolling over the stings served as a painful reminder that I had been viciously attacked by some sort of wasp.
Conversations with other cyclists revealed that this is actually a somewhat common phenomenon, but I'm not sure if that makes me feel better or worse. Better because I'm not alone in this experience, but worse because it's likely to happen again.