Exploring the community composition of bees in an east Tennessee garden experiment

The composition of native pollinator communities impacts many things from conservation efforts to home gardening. Here we use data gathered during three years of pollinator collections to examine the composition of the visiting bee community in a garden experiment. From 2019-2021 we grew 18 species of native perennials from three plant families (Asteraceae, Fabaceae, Lamiaceae) in replicated garden plots at five sites in eastern Tennessee. Sites were composed of four plots, each containing six plant species grown in rows of four individuals. Three plots contained plants from a single family, with the fourth consisting of two species from each family. Surveys were conducted weekly from mid-April until October. At every plot, each flowering species was observed for five minutes and insects contacting the reproductive parts of the plant were collected with an insect vacuum. Chambers were changed between observations, labelled and frozen until the end of each season. Specimens were then pinned, labelled, identified, databased, and verified by Sam Droege. We conducted genus-level analysis on 9,562 bees across 32 genera of bees and found few significant differences in percent composition between years. Sampling within a 50m radius surrounding our plots showed no significant difference in beta diversity across surrounding land use types. Plot-level analysis of our data shows distinct bee communities visiting each of the plant families studied. This survey of pollinator community composition provides essential information for conservation efforts and this research can be used as a baseline for pollinator conservation in eastern Tennessee.