Plot:
The narrator extolls the virtues of how insects are superior to man. In the desert, Frank, an oil company surveyor, and Pepe, his assistant,

Badges, we don't need no stinkin' badges...
find Grant Phillips and Doreen roaming the desert. Taken to a nearby hospital, the hysterical Grant rambles about
monsters and Dr. Araña's lab before starting his story.
Begin the flashback tale with the arrogant narrator. Dr. Masterson goes to see Dr. Araña's lab.

Of course, I can say SCIENCE like in the Thomas Dolby song...
Masterson sees the extent of Araña's work about taking the growth hormone from a woman and transplanting it a tarantula
which grows as a human woman with telepathy and regeneration. Of course, all these things mean that Araña can rule the world....Bwa-Ha-Ha-Ha...Masterson swears to stop this evil scheme. Tarantella knocks him out.
Newspaper montage explains that Masterson has lost his mind and was found in the desert. He was taken to an asylum
but seems to easily escape.

A place with a Wet Sombrero contest does sound a bit tacky...
A little while later, Masterson reaches a bar. He meets Grant Phillips (pilot), Doreen, Jan Van Croft(Doreen's fiancee), and Woo (Jan's servant). George (nurse from the asylum) has reached the bar and found Masterson. Tarantella starts dancing at the bar.

It may not be the Bat-tusi but better than your lame dancing.
Masterson seems entranced until he pulls out a gun and shoots her.

You're not a good dancer and this shoudld stop you...
This does disturb most of the barflies.
Masterson wants to protect Doreen and the others. They head for the airport and take off in Grant's airplane which isn't in 100% condition if it were a matchbox with a rubberband it probably be in better shape. It still takes off before teh police can get there. In mid-air, an engine goes out, Grant has to make an emergency landing on top of a mesa in the desert.
That night, They launch the only signal flare. George heads out to go exploring and starts screaming in the bush. The others head out and find George's corpse.
Back at camp, Doreen is starting to get chummy with Grant. Apparently, she's starting to realize that her fiancee isn't the manly heroic movie type. Woo heads out to find a family heirloom of Jan's.
Woo heads to Arayna's lab. He reports that he's brought Masterson back the others can be used for experiments. Woo doesn't leap to the idea of scientific experimentation fast enough. Arayna has Tartantella eliminate Woo.
Grant finds Woo's body later. A giant spider attacks Jan. Dwarves and Tarnatula women grab the rest.
Back at the lab, Dr. Araña restores's Masterson's mind. He's needed for the mad scientist great plan. Doreen attacks Tarantella. Grant grabs Arayna. Masterson fixes a chemical formula to destroy the lab. He sends Grant and Doreen from the lab first and blows the lab killing himself and Arayna.
Back at the hospital, Grant finishes the story when Doreen awakens. Theguys around don't believe Grant's hysterical tale. The narrator smugly explains that there is nothing to Grant's tale. Back in the desert, the Tartantula Women are still on the mesa.