A week or so ago, I shot one that looked very much like your recent post. Don't think I kept it, though.

Try to get a good view of the relative lengths of the 1st and 2nd antennal segments: that's the most crucial key character separating the two known CA species. (And also, a clear wing venation shot, so you can determine whether or not it's in subgenus Empidigeron.)

But, honestly, it seems to me there may likely be more undocumented and undescribed CA species in subgenus Empidigeron...either that, or the two CA species are quite variable, and it would be helpful to photo-document a lot more specimens to help clarify the the degree and characteristics of that variation. Although workers like Hall, Evenhuis, and so many before them have amassed and organized a huge amount of info on Bombyliidae, it's such a huge group that (like so many taxa), in order to make the kind of progress many of us would love to see, one would need a battalion of widely distributed and serious workers photographing in the field, collecting, analysing, curating, disseminating resutls, etc.. [Hmmm...that kind of sounds like something that could be helped along by the spirit of BugGuide :-]

Photos are attached and, thanks to a nudge from you, I'll also post. I'd hesitated because we seem to have a ton of Geron images and mine aren't sharp.

(Written a bit later)
The post:

I wrote a response under that post.

I may have some oldies on file; will check now that I understand they're wanted.

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