The second phase of the MN Bee Atlas focused on the plants that tunnel-nesting bees use to build their nests, while continuing to learn about distributions, phenology, and habitat associations. Many tunnel-nesting bees use leaf pieces, chewed leaves, plant resins, or plant hairs to line and cap the nests where their offspring will develop and over-winter. The Bee Atlas is using DNA and resin analysis to identify which plants the bees are using so that we can understand this important part of their habitat needs.

We distributed nesting blocks to volunteers in spring 2022 and 2023, to be placed in areas such as county parks, nature centers, and DNR Scientific and Natural Areas (SNAs) across the state. Bees nested in these blocks, and volunteers observed the blocks to see when bees are most active and what they build their nests out of. When blocks were returned to our lab in the fall, Bee Atlas staff took samples of nesting material for analysis and reared larvae from the nests to adulthood for identification. See our results here.