For people not allergic to bee stings, a quarter of a teaspoon of meat tenderizer (containing the active ingredient papain) disolved in a couple of teaspoons of water (enough to make a paste) should be applied to the sting.
Source:
Post-Crescent, 7-30-1985
Notes:
For more information on insect bites, see the InteliHealth article on Insect Venom Allergies.