Steve Ditko: "Who came up with the specific name, Spider-man, is for Stan and Jack to resolve. Stan said Spider-man would be a teenager with a magic ring that could transform him into an adult hero -- Spider-man. I said it sounded like the Fly, which Joe Simon had done for Archie publications. I didn't believe Jack was involved in that feature because the issues I had seen lacked the usual Kirby flair."
I accepted Ditko's observation that Jack wasn't involved in the creation of the Fly as fact because I suspect Steve is a very knowledgeable expert on comics, but I recently had a chance to look at the first 4 issues of the Fly for the first time, and I think Ditko was mistaken in this case. I think Jack was involved in the production of The Adventures of the Fly # 1, 2. Here are the stories/art I think Jack worked on:
From Aug 1959:
Adventures of the Fly # 1 : Cover
Adventures of the Fly # 1 : "Strange New World of the Fly" (6 pages)
Adventures of the Fly # 1 : "The Fly Strikes" (2 pages)
Adventures of the Fly # 1 : "The Fly Discovers His Buzz Gun" (5 pages)
Adventures of the Fly # 1 : "Come Into My Parlor" (7 pages)
From Sep 1959:
Adventures of the Fly # 2 : "Marco's Eyes" (8 pages )
Adventures of the Fly # 2 : "Master of Junk-Ri-La" (6 pages)
Looking at the artwork in these books, it looks like Kirby was phasing out of his working relationship with Joe Simon. Adventures of the Fly # 1 features four stories and a cover by Jack, then Adventures of the Fly # 2 has two stories by Jack. Other than that, the rest of the artwork in the first four issues appears to be by other artists, much of which could be described as Kirby "homage," or Kirby-influenced.
This cover has been frequently attributed to Kirby, and I'm far from an expert on Simon/Kirby, but my guess is that Jack probably didn't draw the cover for Adventures of the Fly # 2. I suspect whoever was the artist for this cover swiped the composition from Captain America Comics # 7 in order to mimic the Simon/Kirby "house style" -- which was Jack's visual storytelling style since Jack did the layouts and pencils. My guess is that Ditko knew enough about Jack's art and approach to artwork to suspect this piece was not by Kirby, so Steve assumed Jack wasn't working on the character -- other artists were swiping from Kirby art to try and copy his dynamics. Here are two more examples of very obvious Kirby swipes in Adventures of the Fly # 2 (compared to the original publication in Foxhole # 2):
"Hot Box," Pg. 2, panel 1 (Foxhole # 2, Dec 1954)
"Sneak Attack," pg. 1, panel 5 (Adventures of the Fly, # 2, Sep 1959).
"Hot Box," pg. 2, panel 2 (Foxhole # 2, Dec 1954)
"Sneak Attack," pg. 1, panel 3 (Adventures of the Fly, # 2, Sep 1959).
I'm not sure who the artist is for the "Sneak Attack" story but it clearly is not Kirby, and appears to be filler to pad out the rest of the issue. In my opinion, this is a fairly poor imitation of Jack. All of the elements that made these panels dynamic in the Foxhole publication are gone -- they are merely tracings to fill space. Jack certainly had no need to trace himself in this fashion.
Adventures of the Fly #3 features no original Kirby artwork at all, so if Ditko had picked that book up off the stands he would have rightly assumed Jack was not working on that title at all. Adventures of the Fly # 4 has a few panels that look like they may be part of an unfinished Kirby story, but they also may be examples where other artists were tracing old Kirby drawing trying to copy his style, or attempting to use Kirby dynamics.
Aside from the stories filled with Kirby swipes, it appears that without question Jack did work on several entire stories that bare his unique stylistic imprint. From Adventures of the Fly # 1, here are three examples of pages by Kirby.
Adventures of the Fly # 2. Here are 3 examples of pages where the story and artwork is clearly by Jack Kirby.
Adventures of the Fly # 2 (pgs. 21, 28, and 34).
To me, those pages were obviously penciled by Jack, and there are several other examples like the "wide angle scream" double-splash pages that are nothing short of extraordinary.
I want to make it clear, I'm not accusing Ditko of lying or exaggerating to strengthen his argument concerning the creation of Spider-man -- to me, there is no doubt Ditko deserves the title given to him by Stan Lee as "co-creator" for the Marvel Spider-man: his design of the Spider-man costume resonates with millions of people worldwide and his contributions to the first several years of stories were very important -- I'm just pointing out that if you take a closer look at the history, you find at times individuals who were there may make mistakes or get information wrong.
In this case, despite some examples of other artists swiping his style, in my opinion, it's obvious to me that Jack Kirby was involved in the first 2 issues of the Fly. Jack drew entire stories himself, and it is very possible Jack may have contributed significant story elements to those tales, so I doubt it would shock most comics experts to learn that Jack used elements of his original 1959 Fly for the first design and origin of the Marvel Comics Spider-man in 1962.