Moved from Sphiximorpha.

If this were Sphiximorpha, then...

1) The waist would be only moderately (and noticebly less) constricted...here it's quite constricted, as in Polybiomyia.

2) It would presumably "pan out" nicely in the key for Sphiximorpha in Thompson(2012). But it doesn't yield a consistent result there (in particular, it doesn't agree with either of the two species from AZ included there).

In Shannon(1925), this male would appear to go the terminal entry of his key for the genus he called Ceroiodes. That terminal entry lumped together two names: Ceriodes signifera (Loew) 1853 and Ceriodes willistoni (Kahl) 1897.

Loew's original description (in German) appears here as Ceria signifera, and it was redescribed here (in English) by Williston in 1866. Williston's description is not in accord with the photo in this post (e.g. he states "the immediate ground upon which the antennae are inserted is yellow", whereas that ground and most of the surrounding portion of the frons here are solidly black...except for the narrow, uninterrupted, whitish-yellow margin along the inner orbits of the eyes). Also, note that Jeff Skevinton's current checklist for Syrphidae lists Ceria signifera Loew under the name Ceriana (Polybiomyia) signifera...i.e. strictly speaking not circumscribed there as a Sphiximorpha.

Shannon's Ceriodes willistoni was originally described by Kahl here as Ceria willistoni, and there are many morphologically coherent posts of that species on BugGuide for comparison with the post here. A number of differences are apparent between the image in this post and those of S. willistoni below...the most conspicuous being the absence of the lateral yellow stripes along the edges of the metanotum between the transverse suture and the scutellum. Another difference in the image here (not described by Williston, but apparent in other BugGuide posts of S. willistoni) is the uninterrupted narrow yellow border between the inner orbits and the entirely black center of the frons. In all the current S. willistoni posts, that border is interrupted by two narrow, black, lateral "bands" (or spots) radiating from the central black of the frons to the inner edges of the eyes. Compare with the images of S. willistoni below:

           

It's also important to keep in mind that this could very well be Polybiomyia...the only character separating the two genera (or subgenera per Skevington's current view) is a membranous vs. sclerotized connective bridge between the hind coxae...which is almost never visible in typical BugGuide photos. Treated as Polybiomyia, this would appear to go to P. sayi in Shannon(1925)...and the above inconsistencies would seem to become consistent with that species (which, among other things, was described from the Huachuca Mountains). Compare with:

       

Moved from Thick-headed Flies.