Specialist Bees of the Northeast: Host Plants and Habitat Conservation

Habitat conservation is performed in North America to support populations of managed and wild pollinators. The current recommended plant selections for northeastern pollinator habitats primarily provide resources for common or generalist pollinators. However, such plants may not benefit uncommon or rare northeastern specialist pollinators, whose populations are susceptible to harm from anthropogenic threats. This manuscript presents the first catalog of native specialist bees and associated host plants for the Northeast. Approximately 15% of northeastern native bee species are pollen specialists, represented by 6 families, 15 genera, and 61 species of bees that restrict pollen foraging to 23 families, 33 genera, and 201 possible species of native host plants. Specialist bees are associated with non-graminoid forbs and non-coniferous woody plants in nearly all major northeastern terrestrial and wetland habitats. Herein, I identify and discuss vulnerable bee-plant associations and suggest greater emphasis on research and restoration efforts. I recommend that northeastern pollinator-conservation practice specifically target specialist bees.