This reminds me of the last time I did the Michaux Terror at Teaberry race. It was probably four years or so ago and I was having a decent but not great day - I was chasing second or third place (can't recall which) with the guy in sight but just out of reach for like 12 miles. At one point there was a section of the course that was hike-a-bike because of a set of downed trees. I hopped off the bike as pro-like as I could and was running over the tree pile and managed to step right in the middle of a hornets nest. At the time, I did what one should always do in that situation: I panicked, started screaming like a little girl, tossed my bike to the side and started to run like hell while frantically waving my hands all over the place. After they had their fill of stinging me (I think I got stung seven times or something), I retrieved my bike and decided that my chase was over and I basically took it easy the rest of the race. Until then I didn't know if I was allergic to their sting or not, so luckily that turned out to be a negative.
Bee stings on a bike ride suuuuuuuuuuck, but at least you can take solace in knowing that if you react anything like I do, then at least you would have provided entertainment for anyone who happened to see it happen.