Hi:
From Mark Winston's "Biology of the Honey Bee", pgs. 29-30,
"The venom injected when a worker stings is a mixture of proteins and
peptides, the major component being a protein called melittin. Venom
contains other compounds such as hyaluronidase, phospholipase A, acid
phosphatase, and histamine. ...The complex nature of the venom may be due to
the wide variety of insect and vertebrate pests and predators which might
attack a bee colony..."