Hi Guys! In the past 15 years I've examined many photos from myself and others that we thought were one species or the other (regarding females of these two species), but then specimen examination in the lab (often of the same individuals that were photographed), personally with John Abbott has revealed we were wrong. I don't trust the dark mark stuff on the end segments and found it very subjective and ambiguous in my experience. If you have time take a look at this iNat record:
http://www.inaturalist.org/observations/3134121 in which I asked Dr. Abbott to look at since he happened to be staying at my house on a visit when I was commenting on it on iNat. I think the bug in that record is a dead ringer to this one. I am not saying this is not apicalis, just that I don't think you can say it is based on the photo. After collecting many hundreds of female apicalis and moesta over a decade or more, I think that this is a more complex issue than many folks realize when you are talking photos only. In the big picture, this issue is not important, but I just personally feel many of these tricky IDs of female Argias of these two species are more complex than we would like. Just my opinion and this record can stand as far as I'm concerned. So, just my take on it all for what it is worth. I have been spending more time on iNat lately rather than acting an an editor with odonates on BG and for that I apologize.

Nick Block also thinks this is apicalis, so I'll just get off my soap box and leave these alone.

Two weeks prior to this photo, in the same place, I took this photo: http://bugguide.net/node/view/1310920

How are you eliminating a blue form female Powdered Dancer? Blue-fronted and Powdered females are very difficult to tell apart ion photos.