‘Sulphur’ butterfly

I cannot usually distinguish Orange Sulphurs (Colias eurytheme) from Clouded Sulphurs (Colias philodice), so I submitted three images for ID.
» There may also be a hybrid, Colias eurytheme x philodice, further complicating identification.

» ID’ed as Colias eurytheme or “Orange Sulphur”: [ Butterflies & Moths of North America ] [ BugGuide ]
» Species pages, Colias eurytheme, “Orange Sulphur”: [ BAMONA ] [ BugGuide ] [ UK Butterflies ]
» Species pages, Colias philodice, “Clouded Sulphur”: [ BAMONA ] [ BugGuide ] [ UK Butterflies ]
» UK species: Four species in the genus “Colias”

“One of the most widespread and common butterflies in North America.” —BAMONA

[ IMG_3913S8x8tm :: 60mm ]
Fascinatingly, 4 years ago I posted a photo of an Orange Sulphur with the same file name out of my Canon T2i: IMG_3913. So I’ve taken about 10,000 images since then? Or the numbering started over? Not curious enough to investigate, but I thought it was interesting.

Looking back
1 year ago: No post
2 years ago: “November butterfly”
3 years ago: No post
4 years ago: No post
5 years ago: “TEST [re-]POST for background color [filler]”
6 years ago: “Fall colors”
7 years ago: “That's a lotta needles…”
8 years ago: “Sliding down a slippery slope…”
9 years ago: “Polka-dot Cactus”
10 years ago: “Not much DOF here…”
11 years ago: “Fallen star”