Lessons from the Ohio bee survey: analysis of pan trap data and suggestions for improving specimen richness while limiting specimen numbers

The Ohio Bee Survey aimed to generate the first comprehensive checklist of Ohio’s bees. Funded through the Ohio Division of Wildlife, the three-year survey began in 2020. We drew on numerous volunteer community scientists trained in basic bee biology to deploy 155 pan trap kits in 87 Ohio counties, each at a single location, such as a yard, park, or preserve. A full-time coordinator encouraged weekly sampling from May – September with a weekly email, arranged specimen drop off, organized specimen preparation, and oversaw identification of specimens over the next two years. More than 53,753 identifiable specimens were collected, representing 250 species. Five common species represented more than 42 percent, whereas over half of the species had fewer than five specimens. One season of intensive pan trapping generated fewer species than were documented in neighboring states, suggesting failure to detect some species, despite our large numbers of specimens and wide geographic coverage. To guide future survey design, we estimated sampling frequency needed to capture the observed diversity using a randomization procedure. We also designed a follow-up study to increase richness of bees and fill gaps in our checklist. We net bees visiting plants known to be hosts of specialist bees during timed surveys to examine presence and abundance of both specialist and generalist species. Preliminary results indicate a high diversity of bees and more specialists represented with an order of magnitude fewer specimens. Employing both sampling methods benefits geographic coverage and species representation.