A standardized pan-trap dataset of vouchered wild bee specimens from open-canopy habitats in southern Ontario, Canada, sampled over three consecutive seasons (2014–2016)

This dataset documents wild bee (Hymenoptera: Apoidea) assemblages sampled using standardized pan trapping across five open-canopy habitat units in Hamilton, Ontario, Canada. Bees were collected biweekly from spring through fall over three consecutive field seasons (2014–2016), yielding 187 sampling events.Each sampling event consisted of 30 colored pan traps (white, fluorescent yellow, and fluorescent blue) deployed within a 50 × 50 m plot for approximately nine hours under standardized weather conditions. Specimens from all traps at a site and date were pooled to represent a single event.A total of 9,288 preserved specimens were collected and identified to species or morphospecies using regional keys and taxonomic revisions, with difficult taxa verified by specialists. Specimens were curated, pinned, and labeled with globally unique identifiers.Voucher specimens are deposited in the McMaster University Insect Collection (BDMU), with selected vouchers housed at the University of Guelph Insect Collection (DEBU).