Strategies to reduce the decline of wild bumble bees in North America: are they working?

Abstract

Bumble bees are major pollinators of the world’s agricultural crops and wild plants and, as such, play a key role in maintaining economic prosperity and biodiversity. The decline of wild bumble bees in North America has been well-documented. However, the efficacy of strategies to prevent further decline have not been investigated thoroughly. This thesis involves a comprehensive literature review to examine the extent of, and reasons behind, the decline of wild bumble bee populations in North America and explore whether strategies implemented to prevent further decline are working. Results of this literature review revealed numerous stressors affecting bumble bee populations, but also indicated that reactions may differ between bumble bee species. The necessary species assessments are difficult to conduct because data pertaining to temporal and spatial occurrence are hard to obtain. Novel approaches to collecting bumble bee population data, such as the citizen science program Bumble Bee Watch, are important in augmenting the data collected by researchers. It is essential that existing databases be maintained to support ongoing monitoring. Long term conservation strategies must be established to preserve these important pollinators to ensure strong ecosystems have the necessary biodiversity to support the planet and its inhabitants. Essential areas of focus include habitat preservation and creation, bumble bee health and resource availability, use of pesticides, management of diseases and invasive species, building capacity through partnerships, education and training, research and effective monitoring programs. This information will be important in assessing the success of current mitigation strategies in the conservation and recovery of native bumble bees.