Date of Award
Master of Science in Biological and Environmental Sciences (MSBES)
Plant Sciences and Entomology
Steven R. Alm
Native bees are experiencing global declines due to multiple factors including habitat loss, pesticide use, pathogens, and climate change. Several recent bumble bee studies across New England have documented declines in species richness throughout the region. Bee visitation to different flower species in bloom concurrently can be influenced by actual floral preferences, timing of nectar and pollen presentation, relative abundances of the flower species, and other factors. I assessed bee abundance, diversity, and selective foraging patterns in southern Rhode Island on four planted flower species: white clover (Trifolium repens L.), medium and mammoth red clover (Trifolium pratense L.), crimson clover (Trifolium incarnatum L.), and common selfheal (Prunella vulgaris L. var lanceolata [Barton] Fern.), by conducting quadrat surveys on two randomized floral plots. I also compared the effectiveness of five different methods (flail mowing, slice seeding, rototilling, herbicide, and solarization) in establishing these four species as well as creeping thyme (Thymus serpyllum L.) in turf via floral abundance surveys. Medium Trifolium pratense had the highest number and diversity of bee foragers in 2022. In 2023, this trend shifted, and T. repens and P. vulgaris had the highest bee species richness. Floral visitation varied among bee species, potentially due to selective preferences. Overall, Trifolium spp. and P. vulgaris are valuable floral resources that support a wide range of bee species and should be included in pollinator plantings.
Vieira, Julia J., "BEE VISITATION TO THREE CLOVER SPECIES (TRIFOLIUM SPP.), COMMON SELFHEAL (PRUNELLA VULGARIS) AND CREEPING THYME (THYMUS SERPYLLUM)" (2023). Open Access Master's Theses. Paper 2358.
Available for download on Friday, September 05, 2025