I have been stung three times in my life, in the past three years! First was a bee on the bike (I know because he left his stinger). It was a small hill and I was caught off guard. Luckily there was big shoulder and I was able to do a controlled stop. Being my first sting at the ripe old age of 27 I found it really painful and started crying. It was swollen around the sting and itchy for about a week, Benedryl cream provided some relief.

Second was a black wasp in New Mexico while hiking last month, they call them Tarantula Hawks and it is supposedly the most painful sting. I saw it land on me, swatted it off thinking it was a horsefly. The initial pain was only about 30 seconds but it was swollen and extremely itchy for over TWO weeks. It was a pretty large swollen area making a big puffy ring about 2-3" in diameter around the sting. Benedryl cream again provided some relief but it was discolored for nearly a month!

Third I got stung by something two weeks ago. It didn't swell much, only a small red mark. Itched for a few days.

I know that bright colors and perfume can attract them. Other than that it appears to be mostly bad luck on a bike unless you are disturbing their nest. DH did that recently with yellowjackets which are known to be particularly aggressive anyway. I hope you (and me!) have had your fill of stings. Benedryl will help but if you are made drowsy by the pill form it wouldn't be the best first aid. I carry the pills now since I do not have the drowsy side effects but only about 10% won't get drowsy my doctor claims.