熊蜂的演化历史始于约4000-2500万年前的一次全球降温事件,正值Eocene–Oligocene(始新世-渐新世) boundary,发源地可能在亚洲——这片大陆至今仍保存着最多的早期分化支系和最高的物种多样性。约3400万年前中亚干旱沙漠区域的扩张是其演化过程中的一个早期关键阶段,因为现存最古老分化的熊蜂亚属物种集中分布于该生命禁区南部的山脉或北部的丘陵地带。
2100万年前之后,帕米尔和天山山脉的再次隆升可能为这些早期分化熊蜂的后代提供了气候适宜、生态多样的"桥梁",促进了种群扩散和动物区系交流。向欧亚大陆西部的迁徙呈现两个明显阶段:**低地长吻熊蜂(lowland, long-faced)区系约1100万年前进入欧洲,而山地短吻熊蜂(montane, short-faced)**则在约500万年前完成扩散。在向东迁徙的路线中,部分谱系通过白令陆桥(当时存在陆地连接)进入北美,并于800-1200万年前抵达中美洲。最引人注目的是,约300万年前某些物种成功拓殖南美洲,至今在这片大陆仍生存着某些特有的熊蜂物种。
虽然绝大多数蜂类都是独居的,Bombus却要么是真社会性要么是寄居的(inquiline)。
Figure 1. Interconnected life cycles of a free-living host bumblebee species (A–G) and its associated cuckoo species (H–M). (A) Queen hibernating; (B) queen feeding; (C) queen founding its colony; (D,E) colony developing with workers; (F) emergence of males and young queens (lighter individuals on the left); (G) mating of a young queen and male; (H) cuckoo queen hibernating; (I) cuckoo queen feeding; (J) cuckoo queen hidden in the colony of its host; (K) cuckoo queen killing the host queen; (L) host workers now working for the cuckoo queen, and emergence of cuckoo males and young cuckoo queens (lighter individuals on the right); (M) mating of a young cuckoo queen and cuckoo male. The depicted colors for bumblebee hairs are for illustration purposes only and are not based on an actual host–parasite species pair. (Figure by Olympe Tritto.)
在真社会熊蜂中,创始蜂王经历独居阶段建立蜂群,