The Swarm is a 1978 American horror film about a killer bee invasion of Texas. It was adapted from a novel of the same name by Arthur Herzog. The film was directed by Irwin Allen, and the cast includes Michael Caine, Katharine Ross, Richard Widmark, Richard Chamberlain, Olivia de Havilland, Ben Johnson, Lee Grant, José Ferrer, Patty Duke, Slim Pickens, Bradford Dillman, Fred MacMurray and Henry Fonda.
A group of soldiers led by Major Baker, is ordered to investigate the basement level of a missile base, which appears to have been attacked, and the garrison all but wiped out. After Baker contacts his commander, General Slater, they begin to investigate a civilian van found parked at the base. It is revealed to be owned by a scientist, Dr. Bradford Crane, one of the few survivors of the attack, but not someone stationed at the base. Slater orders two helicopters to track a large airborne mass moving slowly away from the base. The mass is revealed to be a swarm of bees, which engulfs the two helicopters, killing their crews. Crane insists to Slater that the base was attacked by this swarm, composed of deadly African killer bees. Slater doesn't trust Crane, but Helena Anderson, one of the base's doctors, supports Crane's story.
Meanwhile, in the countryside, a family is attacked by a swarm of the bees. Their teenage son, Paul Durant, manages to escape in a Mustang, although he is also stung, and crashes into the Marysville town square, where the citizens are preparing for the annual flower festival. The boy is brought into the hands of military personnel, where he hallucinates a vision of giant bees attacking him, on account of the after-effects of the bee stings.
Much to Slater's annoyance, Crane is put in charge by the President and calls in many experts to help. Wheelchair-bound Dr. Walter Krim arrives at the base and confirms to Crane that the very war they have feared for a long time has started with the bees. At the gates of the base, Slater must confront angry country bumpkin Jed Hawkins, who demands to see the dead body of his son, who was killed by the bees. Hawkins takes the body bag and departs, leaving the entire watching crowd silent over the loss. Slater suggests airdropping poison on the swarm, but Crane considers the ecological possibilities of the situation, and overrules him, instead focusing on a solution that will kill the bees without harming people and the environment.
Recovering from his earlier bee attack, Paul and two of his friends go in search of the hive to firebomb it, which results only in angering the bees, which make their way to Marysville and kill hundreds, including some children at the local school. Crane and Helena take shelter at the local diner, with pregnant café waitress Rita. Reporter, Anne McGregor, watches from the safety of her news van, hoping to get some exciting footage about the siege. After this most recent attack, Slater suggests evacuating many of the townsfolk in a train. However, the bees engulf the train as well, causing it to derail and crash, killing most of the occupants including a love triangle made up of school superintendent, Maureen Scheuster, retiree, Felix Austin, and town Mayor, and drug-store owner, Clarence Tuttle.
Confined to a hospital bed, Rita gives birth to her child, falling in love with the doctor in the process, but Paul, who has fallen ill again, succumbs to the after-effects of the stings and dies, devastating Helena. The savage swarm heads for Houston, so Crane drops eco-friendly poison pellets designed by Dr. Hubbard, on them, but the bees ignore the pellets, evidently intelligent enough to sense danger. Working on an antidote to the bees' venom, Dr. Krim, self-injects to keep track of the results, although the trial proves fatal, and Krim dies from the effects of the venom. Meanwhile, nuclear power plant manager Dr. Andrews, is convinced that his plant can withstand the attacks of the bees, ignoring the warnings of Dr. Hubbard. However, at that moment, the alarm sounds and the bees invade the plant, killing both Andrews and Hubbard, as well as completely destroying the plant and wiping out an entire town.
Washington orders that operations to stop the bees be placed under military control and Slater takes charge. He orders the evacuated city of Houston to be deliberately torched by soldiers with flame-throwers, hoping the conflagration will destroy the swarm. Helena, who was stung during the attack on Marysville, falls seriously ill again. Crane analyzes tapes from the original bee attack of the base and comes to the conclusion that their alarm system attracted the swarm into the base as the sound resembled a signal from the swarm's queen. The bees break into the headquarters building so Slater and Baker use a flame thrower to allow Crane and Helena to escape, but at the cost of their own lives. Helicopters successfully manage to lure the bees out to sea, placing floating buoys, with speakers emitting the sound Crane discovered, into an area of water doused with oil. When the swarm arrives, the oil is set ablaze by missiles fired from the nearby coast, destroying all of the bees.
- Michael Caine as Dr. Bradford Crane
- Katharine Ross as Helena Anderson
- Richard Widmark as General Thaddeus Slater
- Richard Chamberlain as Dr. Hubbard
- Olivia de Havilland as Maureen Schuester
- Ben Johnson as Felix Austin
- Lee Grant as Anne MacGregor
- José Ferrer as Dr. Andrews
- Patty Duke as Rita
- Slim Pickens as Jud Hawkins
- Bradford Dillman as Major Baker
- Fred MacMurray as Clarence Tuttle
- Henry Fonda as Dr. Walter Krim
- Cameron Mitchell as General Thompson
- Christian Juttner as Paul Durant
- Morgan Paull as Dr. Newman
- Alejandro Rey as Dr. Martinez
- Don "Red" Barry as Pete Harris
The film was announced in 1974 at the height of the horror movie craze. It was part of $38 million worth of projects Irwin Allen had lined up, others including The Day the World Ended (a project which was retitled and released in 1980 as When Time Ran Out....). The script was written by Stirling Sillipant, who had written The Towering Inferno for Allen. He said in December 1974 that Allen hoped to start filming in April 1975. Production was delayed in part because Allen decided to leave Fox for Warner Bros.
Estimates of the numbers of bees used in the production ranged between 15 million and 22 million, including 800,000 bees with their stingers removed to enable the cast to work safely with them. A total of 100 people were employed in the production to care for and transport the bees during the film shoot. Only one cast member, Olivia de Havilland, was stung during the production.