This was filmed as "The Spider". Prior to completion, the title was changed to "Earth vs. The Spider" and that was used for the main title on the film itself. When La Mouche noire (1958) became a blockbuster for 20th Century Fox, American International decided to ride on their success by changing the title back to simply "The Spider" on all advertising material. The main title on the film itself was never changed.
The city block that Carol and Mike walk down at the beginning of the movie is part of the famous Universal Courthouse Square backlot, seen in countless films over seven decades. The street this block runs along is the very same one that Marty McFly uses to catch the lightning bolt charge and return to 1985 in his DeLorean.
The town's theatre is playing a double feature of Le Fantastique Homme colosse (1957) and La révolte des poupées (1958). Both were recent Bert I. Gordon films also released by American International.
At 16:16 when the teacher phones the sheriff, he only dials four digits instead of the usual seven. This may not be a mistake. In the mid-20th century, some small communities with their own local telephone exchange only required dailing the final four digits when calling within the community.