The Deadly Mantis is a 1957 American science-fiction monster film produced by William Alland for Universal-International. It was directed by Nathan Juran from a screenplay by Martin Berkeley based on a story by producer William Alland. The film stars Craig Stevens, William Hopper, Alix Talton, and Pat Conway.

The film was released in 1957 as a double feature with the spy film The Girl in the Kremlin. In February 1997, The Deadly Mantis was featured on an episode of Mystery Science Theater 3000.

Ford gathers top scientists, including Professor Anton Gunther (Florenz Ames), to examine the object, but when they cannot identify it, Gunther recommends calling in Dr. Nedrick Jackson (William Hopper), a paleontologist at the Museum of Natural History.

When Ned gets the call from Ford, he is helping museum magazine editor Marge Blaine (Alix Talton) plan her next issue, and dodges her questions as she begs him for a big scoop. Later, after examining the object, Ned recognizes it as a torn-off spur from an insect's leg, and soon guesses, from evidence that the creature ate human flesh, that it must be a gigantic praying mantis. Meanwhile, in the Arctic, the people of an Eskimo village spot the mantis in the sky, and although they hurry to their boats to escape, it swoops down and kills several men.

Ned is sent to Red Eagle One to investigate further, and upon leaving, discovers that Marge has managed to get permission to accompany him as his photographer. They reach the base, where all the men, including Joe, are smitten by Marge. That night, Marge and Joe join Ned in his office and discuss the creature, not realizing that it is drawing close to the office window. Marge suddenly catches sight of it and screams, and the bug attacks the building. Although the full unit opens fire on the mantis with automatic rifles and a flame-thrower, it is unscathed and moves away only after planes encircle it.

Hours later, the base remains on red alert, but they finally hear that the bug has attacked a boat off the Canadian coast, which means, Ned calculates, that it is flying at a speed of 200 miles an hour. Ford calls a press conference to announce the bug's existence, and asks the Ground Observer Corps to track its whereabouts. Over the next few days, Ned, Marge and Joe track the bug's progress with the help of military and civilian observers. Late one night, Joe drives Marge home, stopping briefly to ask for, and receive, a kiss. They are distracted by a report of a nearby train wreck, and although they assume it to be an ordinary accident, soon after, a woman leaving a bus sees the mantis, and all emergency personnel are put on alert. The mantis is then sighted in Washington, D.C., atop the Washington Monument.

Joe is one of the pilots who attempt to drive the mantis toward the sea, but a dense fog throws him off course, and he flies directly into it. As the wounded mantis drops to the ground and crawls into the Manhattan Tunnel, Joe safely parachutes to the ground. Ford leads a team that seals off the tunnel, filling it with smoke to provide cover for Joe and his special unit of men, who enter the tunnel armed with rifles and three chemical bombs. They creep past wrecked cars until suddenly the bug appears in the fog only a few yards ahead of them. They shoot at it, but it lumbers on, forcing them backward. The mantis seems immune to the ammunition and the first chemical bombs until, only feet from the tunnel entrance, Joe throws a bomb in its face, and it collapses, dead.

Later, Ford, Ned, Joe and Marge enter the tunnel to examine the bug. Marge photographs its face while the men walk around its side, but Joe suddenly sees the mantis' arm move, and runs to protect Marge. Although Ned explains that the bug's movement was merely an autonomic reflex, Joe takes the opportunity to pull Marge into an embrace.

Production
The Deadly Mantis was the first science fiction film made by director Nathan Juran, who says the opening sequence was his idea.

To create the film's special effects, a 200-foot (61 m) by 40-foot (12 m) long papier-maché model of a mantis, with a wingspan of 150 feet (46 m) and fitted with a hydraulic system, was built. Two smaller models were also built, one that was 6 feet (1.8 m) long, and another than was 1 foot (0.30 m) long; these were used for the scenes where the mantis walked or flew. Shots of a real praying mantis were used for the scene in which the deadly mantis climbs the Washington Monument.

The film utilized stock Air Force footage taken from short films such as "Guardians All", "One Plane - One Bond", and "SFP308." The footage of the Eskimo village was taken from Universal's 1933 film S.O.S. Iceberg.

Reception
The film received a rating of 4.5/10 on IMDb and has a current rating of 38% on review aggregator website Rotten Tomatoes. The website Atomic Monsters looked at the film in a somewhat positive light, giving it a "radioactive rating of 5 atomic blasts out of 5".

Home media
Universal released The Deadly Mantis on DVD in a boxed set called The Classic Sci-Fi Ultimate Collection Vol. 2, which includes four other films: (Dr. Cyclops, The Land Unknown, Cult of the Cobra, and The Leech Woman).

Monster from Green Hell is a 1957 science fiction B movie originally released as a double feature with the 1957 film The Brain from Planet Arous. It was then re-released in 1958 as the top half of another double feature with the English-dubbed and re-edited version of the Japanese kaiju film Half Human.

​In Libreville, equatorial Africa, the territorial agent makes plans for them to travel to meet Dr. Lorentz. Once the safari is ready, Mahri, an Arab, leads Brady and Morgan on the four-hundred mile trek to Lorentz's hospital. The safari battles brush fires, fever, drought and storms, eventually reaching the Lorentz compound where Lorna informs them that her father has not returned from a journey to Green Hell. Later, Arobi arrives with the news that Lorentz has been killed by a monster living in the cauldron of a volcano and gives Brady a giant stinger he removed from the doctor's shoulder. After Brady analyzes the stinger, he confirms that it belongs to a giant, deadly wasp. Although Brady advises Lorna to stay at the hospital, she insists on accompanying him, Morgan, Mahri and Arobi to Green Hell.

​When the native bearers learn of the destination, they desert, and although Lorna is able to shame several local villagers into helping, they, too, run off when the group comes upon a deserted native village littered with dead bodies. After Brady expresses his concern that the insects may be multiplying rapidly and could eventually overrun all of Africa, he states that they must destroy the queen and her immediate colony. Brady then explains to Mahri that he has brought small grenade-like bombs, filled with a special explosive, to use against the monsters. As they move closer to the base of the volcano, which shows signs of an imminent eruption, they hear a very loud, buzzing sound.

When Brady looks down from a ridge above the volcano, he finds the queen wasp and several gigantic workers. The four men toss grenades into the bowl, but the explosions only serve to anger the wasps. Lorna and the men are pursued by one of the wasps, the size of a large building, but hide in a cave that it cannot enter. The group escapes through another entrance and, just as they emerge, the volcano erupts, spewing massive lava flows that destroy all the wasps in the conflagration. Morgan then notes that nature has a way of destroying its mistakes.

Production and reception
Monster from Green Hell contains stock-footage from the 1939 film Stanley and Livingstone. One of the filming locations was Bronson Caves located in Griffith Park, Hollywood.

The film's working title was alternately Creatures from Green Hell or The Beast From Green Hell. Although the print viewed included a 1956 copyright statement for Gross-Krasne, Inc., the film was not registered for copyright at the time of its release. However, the film was registered for copyright years later by Wade Williams on November 26, 1984, under number PA 180-809.

Monster from Green Hell has received negative reviews from the few critics on Rotten Tomatoes. It holds a 2/5 average rating on Rotten Tomatoes and a low 3,3/10 on the Internet Movie Database.

In popular culture
In the Pop Culture; The 1960s toy line from Remco which featured giant bugs vs. the military, the largest of the mechanical bugs 'Horrible Hamilton' is designed after the giant wasps in this film. Another of the mechanical bug toys in this line included a giant 'ant' or 'spider' which was designed after the giant ants in the film Them!, 'The Spooky Spider'.