Example test images showing coarse scale intraspecific variability in appearance. Bombus melanopygus are (A) without orange coloration in the southern part of their range but (B) with orange on the northern end. (C) A B. affinis worker displaying its characteristic rusty-colored patch on T2 of its abdomen, however (D) the patch is usually absent or reduced on queens. B. fervidus has (E) extensive yellow coloration in the eastern part of its range, but (F) is more extensively black in the western end. Photo credits: (A) Andrea Kreuzhage, (B) Scott Ramos, (C, D) Heather Holm, (E) Sue Gregoire, (F) Asa B. Spade.