Structure of Bee Communities in Marginal Lands of the Puget Sound, USA

Wild bee communities in urban ecosystems are often challenged by habitat fragmentation and low floral diversity. In such settings, marginal land surrounding airports or in power line corridors may support bees, even with small habitat patches. However, temporal surveys of wild bees are lacking for many urban areas such as the Puget Sound region of western Washington State, USA. Here, we conducted wild bee surveys at three peri-urban sites in the Puget Sound over 7 years. Specifically, a standardized protocol was used to sample wild bee communities monthly from April to October at two sites associated with airports and one site in a power line corridor. In total, our surveys collected 25,441 specimens representing 118 confirmed species within 24 genera, with individual subsites having between 15 and 35 species in any year. The Halictidae represented the largest number of individuals collected, with 47% of specimens. By genus, Lasioglossum was the most speciose (n = 21), with Bombus, Osmia, and Andrena also ubiquitous and diverse. Bee diversity was high across spring and summer, and our surveys resolved the presumptive overlap of parasites with their hosts. Our study shows that marginal lands requiring little management can support diverse wild bee communities in urban areas. Our work also provides a baseline for future evaluations of wild bee communities in the Puget Sound and broader Pacific Northwest.