Mown down by bees

Apart from producing the headline of the day — “Bees swarm over Hasty man” — the subsequent story is a sad but interesting story of a 89-year old beekeeper surviving a 100 stinging episode. The lifelong beekeeper, Earl Henry from Hasty in the Ozarks, had been mowing the lawn around a three-super hive when angry bees came out to investigate and punish. (As most beekeepers will know there is something about the smell of cut grass or the vibrations of mowers that aggravates bees.) Henry survived the ordeal and, on leaving hospital, his first plan was to call in bee experts to see if feral bees had bred aggressive traits into his own colony.

There was also an interesting factoid in the story:

... studies [of Africanized bees] said seven stings per pound is considered fatal, and survivors of multiple stings sometimes suffer from poor eyesight and weakened muscles.

The seven stings claim is repeated here, but it's the first time I've heard it. Does anyone know of the original research?