Date of Award:

8-2022

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Biology

Committee Chair(s)

Ricardo A. Ramirez

Committee

Ricardo A. Ramirez

Committee

Lori R. Spears

Committee

Emily K. Burchfield

Committee

William D. Pearse

Committee

James P. Strange

Abstract

Bumble bees play pivotal roles in pollinating wild and cultivated plant communities. Unfortunately, bumble bee populations are declining due to disturbances such as landscape conversion and climate change. Additionally, traps used to monitor pest insect populations often capture bumble bees, leading to a concern that trap captures increase bumble bee mortality. First, I studied bumble bee communities based on land cover and weather variables in agricultural fields in Utah. Bumble bee communities were more diverse in agricultural fields with more agricultural land in the surrounding area, low temperatures, and high humidity during the growing season, and less diverse in fields with more urban land, high temperatures and low humidity. However, differences in species among sites suggest that all agricultural fields from this study have high conservation value for bumble bees; therefore, management strategies should maintain a variety of habitat types to promote resiliency of bumble bee assemblages. Next, I examined the effects of climate and landscapes on bumble bees in agricultural fields throughout the U.S. Bumble bee assemblages varied based on habitat characteristics, emphasizing that management practices should differ across the U.S. based on the local climate and landscapes in order to conserve bumble bees. I then measured the impact of trap captures on the size and development of field-released brown-belted bumble bee colonies. Only three brown-belted bumble bees were collected from traps, suggesting that these captures had negligible effects on the observed differences in weight and foraging activity. However, this does not mean that all bumble bee species are not affected. Finally, I evaluated the commercial potential of brown-belted bumble bees by determining if they can be successfully raised in a laboratory setting and by identifying the maximum temperature worker bumble bees can withstand before death. Brown-belted bumble bees can successfully be raised in a lab and can tolerate high temperatures, so they should continue to be evaluated for commercial purposes throughout the U.S. Overall, this research increased knowledge to provide more accurate management practices of bumble bee communities in agricultural systems throughout the U.S. and provided a foundation for developing brown-belted bumble bees as a commercialized pollinator.

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