I'm about to fall asleep but real quick, the female dark form Tiger ST has a solid black body while the Spicebush will have spots on the body. The Tiger is usually noticeably larger. Also, the blue scaling comes up much higher on the wings of the Tiger. I'll try to find some pictures for comparison in the next couple of days. Or someone else can feel free to do it, too! Or link us to a website with good pictures. This is a group effort.
