An investigation of wild bee communities in salt marsh and dyke habitats within the agricultural region of Nova Scotia, Canada

Wild bees (Hymenoptera) that visit croplands rely on adjacent habitat to provide essential resources such as pollen, nectar, and nesting locations. This study compared wild bee assemblages on salt marshes and dykes, two coastal habitats proximal to cropland in Nova Scotia, Canada. We hypothesised that dykes would have a greater wild bee abundance and richness compared to salt marshes due to greater floral abundance and richness and nesting habitat availability. Wild bee richness and abundance differences between habitats were not significant. Most notably, Bombus (Latreille) and Megachildae (Latreille) bees were observed visiting a wind-pollinated salt marsh grass, Sporobolus michauxianus (Peterson and Saarela) (Poaceae). Several notable species were also observed, including the Committee on the Status of Endangered Wildlife in Canada species of concern, Bombus terricola (Kirby) (Hymenoptera: Apidae), and Lasioglossum taylorae (Gibbs) (Hymenoptera: Halictidae), a first Nova Scotia record. Floral abundance and richness were significantly greater in dyke habitats. These results contradict other studies that indicate a tight relationship between wild bees and floral abundance and richness. To help conserve these wild bees and their contributions to agriculture, more research is needed to understand how these species use salt marshes and dykes.