Species Bombus californicus - California Bumble Bee

All black hairs on head vs. yellow in vosnesenskii

Species status for Bombus californicus is controversial as some authorities regard it as merely a subspecies or color variety of Bombus fervidus. Many Bombus californicus, especially from northern and eastern sites, are extensively yellow and therefore closely resemble Bombus fervidus, differing only in presence of black hairs on Terga 1-4. Lack of strong divergence in DNA barcodes and other molecular markers also indicate that this species pair is less distinct than other controversial species pairs.