Bee venom is complex with at least 10 polypeptides present. I posted last time about the pain inducing effects of melittin. What do the other peptides do? Like melittin, apamin, mast-cell degranulating peptide, and a PLA2-related peptide caused inflammatory responses when injected into lab rats. The animals responded by flinching their paws in the area of injection for a brief period but considerably shorter than the response to melittin that lasts 1 hour. Apamin and melittin created hypersensitivity to heat and mechanical stimulus. Apamin effects lasted only briefly. The effects of melittin lasted 48 h. It appears that some of the other peptides have similar effects to melittin and contribute to the short term pain produced by the bee sting. Bees have multiple enemies and some peptides may be more effective against some enemies than others. Short term pain is important for immediate protection. However, the longer period of pain caused by melittin will make the experience more memorable.
Jun Chen, Su-Min Guan, Wei Sun & Han Fu. Melittin, the Major Pain-Producing Substance of Bee Venom. Neurosci. Bull. June, 2016, 32(3):265–272.