It is buzziness time: rearing, mating, and overwintering Bombus vosnesenskii (Hymenoptera: Apidae)

Abstract

Bombus vosnesenskii Radowszkowski, 1862 is one of three bumble bee species commercially available for pollination services in North America; however, little is documented about B. vosnesenskii colony life cycle 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 gynes installed, 62.4% produced brood cells (nest initiation) and 43.2% had at least 1 worker eclose (nest establishment). High-elevation B. vosnesenskii gynes had significantly higher nest initiation and establishment success than low-elevation gynes. However, low-elevation colonies were significantly larger with queens producing 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 min, respectively. Mated gynes were then placed into cold storage for 54 days to simulate overwintering, which resulted in 59.1% of low-elevation gynes surviving and 91.9% of high-elevation gynes surviving. For second-generation low-elevation gynes, 26.4% initiated nesting and 14.3% established nesting. Second-generation high-elevation gynes did not initiate nesting despite CO2 narcosis treatments. Overall, these results increase our understanding of B. vosnesenskii nesting, mating, and overwintering biology from 2 elevations. Furthermore, this study provides information on successful husbandry practices that can be used by researchers and conservationists to address knowledge gaps and enhance the captive rearing of bumble bees.

Assessing the effects of cold storage regimes of North American Bombus Gynes

“…With increased demand on food supply, obtaining food security and quality has come to rely on commercially available bumble bees, especially in greenhouses (Looney et al, 2019;Velthuis & van Doorn, 2006). Efforts to standardize Bombus rearing practices to increase repeatability, maximize profitability and maintain quality have a long history (Carnell et al, 2020;Christman et al, 2023;Milliron, 1967;Röseler, 1985;Rowe et al, 2023;Sladen, 2014;Treanore et al, 2021;Velthuis, 2002;Velthuis & van Doorn, 2006). Despite the successful methods for captive rearing of several Bombus species (Rowe et al, 2023;Strange et al, 2023;Velthuis & van Doorn, 2006), there are still key parts of the life cycle that have yet to be optimized in captive rearing (Röseler, 1985;Velthuis & van Doorn, 2006;Rowe et al, 2023).…”