- if this is supposed to be only on males, why would a female have it? Perhaps the BMNA info is wrong?

My guess at the BMNA (since I don't have it) would be
is the Canadian Biodiversity Information Facility web page discussion between the differences of Aphrodite and the Great Spangled
http://www.cbif.gc.ca/spp_pages/butterflies/species/AphroditeFritillary_e.php


This part discusses the differences:

"It is best distinguished by a combination of characteristics: the forewing upperside margins are not solid black as in many of the fritillaries; the forewing veins lack black sex scales ; there is a large black dot at the base of the forewing (small in some specimens); the submarginal pale band on the hindwing underside is quite narrow, with the dark reddish-orange shading on the basal two-thirds of the wing diffusing into it."

Here is their side by side comparison of different species and the middle one is female, the other two male.

http://www.cbif.gc.ca/spp_pages/butterflies/captions/AphroditeFritillarycap_e.php

Now I am not an expert, but it looks to me the tips of the forewings are darker on the female then on the male. Maybe an expert could help clarify this for us.

There are rules of thumb, but very few unbroken rules. The spot that is supposed to be absent in one species may be there on some individuals, and visa-versa. Generally it works, but not in every single case. It is not unusual for a trait to work better in one gender than another, because one gender may be more variable than the other, and the two genders often look quite different themselves. Using a combination of characters is what works best. As far as I know, male S. aphrodite never has obvious androconia lining veins in the lower outer part of the wing, while male S. atlantis and S. cybele always do. S. atlantis is usually smaller than the others, and has gray eyes (which works only in living specimens) while the others have brownish eyes. The patterns and wing shapes are different too, and with practice you can tell them apart (usually) at a glance, even from a photo, but more easily in person. Often, if you get too involved with analyzing one specific characteristic, you will run into a wall and end up more confused than resolved. Good luck on learning them. You'll get it. At least you're not having to deal with all the western species too - unless you want to :) The eastern species are pretty cleanly distinguishable, and not too difficult once you get the hang of it.

- what identifies this as female?

this question, and I see it's still not really answered. There are several details that identify this as a female. One is the increased proportion of dark marking to light (same markings, just more pronounced); also the orange coloring is less reddish. The males of many Fritillaries (not S. aphrodite) have distinct black androconia ("sex scales") lining the veins of part of the forwings, but these are absent on females (though the veins may be narrowly black in the same place). If you have practice, you can often also tell by the shape and carriage of the abdomen (even from above). It is thicker in the middle, more pointed toward the end, and held a bit straighter (males tend to have a bit of an upward bend to middle of theirs, and the tip is often wider than the middle - usually noticeably in Fritillaries). Yours shows a typical female abdomen shape. Of course their abdomens are flexible, so the shape varies a bit with how they happen to be holding it at the time. From undernieth, especially in some groups (including Fritillaries) you can see the valvae (claspers) of the male at the tip of the abdomen clearly (sometimes visible from above too), and on the females there is a more pointed shape there with a small transverse groove that usually isn't visible through the scales. The scaling and even the structure of the front legs often different too, but that's usually hard to see in a photograph unless it's a close-up detail shot.

Oops, just noticed that I talked about this with the uncropped picture - I'll leave this here anyway.