FIG 1.

Bumble bee life cycle. In the wild, Bombus lantschouensis queens emerge from hibernation in spring, forage (A), and find a nesting location in which to lay eggs and initiate a new colony (B). For the initiation of colonies to produce experimental queens in the laboratory, spring queens were collected from the field (first generation). The worker population grows, and toward the end of the colony cycle in late summer, sexuals (virgin queens and males) are produced (C). Young queens mate with only one male (D) and subsequently hibernate to produce the next generation (E, second generation B). In this study, we assessed three stages of Bombus lantschouensis queens: unmated queens (UQs; virgin queens) following queen eclosion to adulthood in colonies (C), mated queens (MQs; mating successfully with drone, D), and ovipositing queens (OQs; queens actively laying eggs, second generation B).