Extracted from Bumble Bees and Cuckoo Bumble Bees of California by Thorp, R. (1983).
Discussion. B. centralis belongs to the species group which includes B. caliginosusy flavifivns, and varufykei, and appears most closely related to B. flavifivns. It differs from the California color form of B. flav(fions ("dimidiatus" populations) in having red hair on metasomal tergites 3 and 4 and lacking the intermixture of black hairs among the yellow hair of the anterior scutum.
This species exhibits little color variation. Occa-sionally the red hair fades to yellowish in older specimens.
Nests of B. centralis were found by Hobbs (1967b).