It’s buzziness time: Rearing, mating, and overwintering Bombus vosnesenskii Radoszkowski (Hymenoptera: Apidae)

Bombus vosnesenskii is one of three bumble bee species commercially available for pollination services in North America; however, little is documented about B. vosnesenskii colony lifecycle or the establishment of ex situ rearing, mating, and overwintering practices. In this study, we documented nest success, colony size, and gyne production; recorded the duration of mating events; assessed overwintering survival of mated gynes; and evaluated second-generation nest success for colonies established from low and high elevation wild-caught B. vosnesenskii gynes. Of the 125 colonies installed, 62.4% produced brood cells (nest initiation) and 43.2% had at least one worker eclose (nest establishment). High elevation B. vosnesenskii colonies had significantly higher nest initiation and establishment success than low elevation colonies. However, low elevation colonies had significantly larger colonies that produced more gynes on average. Mating was recorded for 200 low elevation and 37 high elevation gynes, resulting in a mean duration of 62 and 51 minutes, respectively. Mated gynes were then placed into cold storage to simulate overwintering, which resulted in a survival rate of 59.1% for low elevation gynes and 91.9% for high elevation gynes. For second-generation low elevation gynes, 26.4% initiated nesting and 14.3% established nesting. Meanwhile, second-generation high elevation gynes did not initiate nesting despite CO₂ narcosis treatments. These results contribute to increased knowledge of B. vosnesenskii nesting, mating, and overwintering biology from dichotomous elevations. Further, this study provides information on successful husbandry practices that can be used by researchers and conservationists to address knowledge gaps and enhance bumble bee conservation.