As people leave post-industrial cities, abandoned homes are demolished and transformed into vacant lots. These greenspaces have been demonstrated to provide habitat for urban wildlife and supply ecosystem services to communities. In the post-industrial city of Cleveland, Ohio, U.S.A., approximately 37% of the state’s bee fauna has been collected within vacant lots. Our goal was to determine if planting native wildflowers (“pocket prairies”) on vacant land would improve these sites as bee habitat. We hypothesized that pocket prairies would support a greater proportion of the regional bee species pool, represented by Metropark grassland bee communities in the suburban landscape, compared to unaltered vacant lots. Using pan traps and hand vacuums, we sampled bees in each treatment from June to September 2019. We collected 1,087 bees representing 24 genera and 81 species. Bees visited over 30 floral species, including native wildflowers and urban spontaneous vegetation. Metropark grasslands supported a higher bee species richness and diversity than urban pocket prairies. Both Metropark grasslands and pocket prairies supported a higher bee abundance, diversity, and species richness than urban vacant lots. Synthesis and Applications: Despite the substantially smaller extent of the pocket prairies, these habitats supported a similar bee abundance to the Metropark grasslands. Bees foraged on intentionally planted wildflowers and non-native spontaneous vegetation, highlighting the importance of managing both components in urban greenspaces. Our results suggest that greening vacant land can improve post-industrial cities as bee habitat.

Urban green spaces can provide important wildlife habitat and ecosystem services. In legacy cities, built structures are demolished as populations dwindle, resulting in vacant land. Vacant land constitutes an opportunity to establish green infrastructure that provides multiple ecosystem services. Our objective was to determine whether establishing green infrastructure on vacant land to manage stormwater could provide insect habitat in the legacy city of Cleveland, Ohio, U.S.A. Two green infrastructure treatments were implemented on vacant land in the historic Slavic Village neighborhood in 2014 and 2015: rain gardens (lower cost) and bioswales (higher cost). We hypothesized that rain gardens and bioswales would support more abundant, species rich insect communities compared to unaltered vacant lots. Wild bees (Hymenoptera: Aculeata) and lady beetles (Coleoptera: Coccinellidae), two insect groups of conservation concern, were sampled during the summer (June–August) from 2014 to 2016 using pan traps and yellow sticky card traps. Local vegetation and temporal variables were measured. Generalized linear mixed effects models evaluated whether insect biodiversity varied with treatment, habitat variables, site, and time. We collected 3,004 bees from pan traps and 5,438 lady beetles from yellow sticky card traps during this study. Bee biodiversity was similar among treatments. In 2014, alien Coccinellidae abundance was higher in vacant lots compared to rain gardens. In 2015 and 2016, alien Coccinellidae were marginally more abundant in rain gardens compared to vacant lots and bioswales, while native Coccinellidae abundance was significantly higher in vacant lots. In the short term, establishing green infrastructure on vacant land can improve stormwater management without compromising the quality of vacant land as insect habitat.