Samia cynthia subspecies identification

Hello!

I have found three sources of the American Samia cynthia subspsecies "advena", but I don't know how to tell if it is truly advena or not. I have not found any good resources on how to key out the different subspecies, and nobody on Facebook seems to know either, so I thought I'd ask here. I've attached two separate photos from two different sources of mine who both received them labelled as "advena". I have received eggs from the photo of the pairing, so I can attach photos of larvae once (and if) they begin hatching. If there are any specific angles needed for identification please let me know!

Also, does anyone know if the different subspecies are even valid? I really can't find much information on them at all.

Thank you for any help you may be able to provide!

Evelyn