A 2003 paper in The Taxonomic Report advocates separating out the northern populations into, at least, a subspecies
borealis. At present BG has 7 images ranging from NC to ME. The NC individuals look different enough from the ME specimen to suspect that these could be different taxa. If the split was made then I would place the MA, WI, ME specimens in
borealis and leave the NC and IL specimens in
anthedon. I can add specimens from NB. Any pros or cons?
Detailed info at
http://www.tils-ttr.org/ttr/ttr-4-5.pdf