Floral preferences of Rhode Island bumble bees (Bombus spp.)

Julia Vieira


Bumble bees (Bombus spp.) are keystone species critical to the pollination of certain wildflowers and crops and many are declining globally in their ranges and abundance. This study augments the Rhode Island Bombus Survey of 2019 by identifying the floral preferences of the 6 currently present Rhode Island Bombus species in order to improve and increase their abundance and diversity throughout the state. Weekly point surveys of Bombus species and forage plants were conducted every 10 m along a 50 m transect, visiting a total of 18 study sites throughout Rhode Island. We identified the top 7 forage plants visited by each Bombus species as well as the forage plants visited by the greatest diversity of Bombus species. Red clover, white clover, and butterfly milkweed were visited by the greatest diversity of Bombus species. Our results allow us to make more precise recommendations for the floral resources needed to improve Rhode Island Bombus abundance and diversity and confirm that only 6 Bombus species are currently present in the state. Floral preferences of our Bombus species should continue to be monitored, and future research should analyze pollen samples from historical Rhode Island Bombus specimens to compare and contrast historical and modern foraging behavior.