Norman Gary, an entomologist and production consultant, was the bee wrangler/handler for this film. All of the "Oh my God, the bees are killing him/her!" shots, where the bees swarm over the victim, were done by him. He also played one of the victims. Gary would do the same two things in this film's sequel, Terror Out of the Sky (1978).
Amazingly, only a very few bee-related injuries occurred on the film's set, a testament to Norman Gary's (the film's bee wrangler/handler) expertise.
This is one of several films about Africanized honey bees (a.k.a. "killer bees") that were released during the 1970s' fear of, and fascination with, their predicted future invasion into the U.S. Southwest via South America in the early 1990s (which actually happened in the predicted time period, but not in the same ways the films had said it would, of course). Other films in this subgenre include Killer Bees (1974), The Bees (1978), The Swarm (1978), and Terror Out of the Sky (1978), which was a sequel to this film.
Literally hundreds of thousands of bees were used for this film.
Two years later, Ben Johnson would star in another killer bee movie, The Swarm.