Abstract We present new DNA sequence data (12S, 16S, and opsin gene fragments) and morphological characters of the male genitalia for a phylogenetic analysis of the bumble bee subgenus Fervidobombus. There is no significant incongruence between the three molecular data sets, and little incongruence between the DNA and morphology. Simultaneous analysis of all the data partitions resulted in a tree that was entirely congruent with the All-DNA tree. Optimization of the geographic locations of the taxa onto the tree topology using dispersal/vicariance analysis suggests a complex picture of spread and diversification of Fervidobombus from the Old World into the southern New World. There is a phylogenetic component to their spread into tropical rain forest, as the two primary rain forest species ( Bombus transversalis and Bombus pullatus) comprise a monophyletic clade, along with a third species, Bombus atratus, which is widely distributed in South America, including lowland subtropical habitats.