Dataset for canopy specialist Hylaeus bees highlight sampling biases and resolve Michener’s mystery

Large parts of the Pacific were thought to host low bee diversity. In Fiji alone our recent estimates of native bee diversity has quickly increased by a factor of five (from four to >22). Here we show how including sampling of the forest canopy has quickly uncovered a new radiation of Hylaeus (Hymenoptera: Colletidae) bees in Fiji. We also show that Hylaeus are more common across the Pacific than previously thought and solve one of Charles Michener’s mysteries by linking the previously enigmatic French Polynesian Hylaeus tuamotuensis to relatives in Fiji. We use systematic techniques to describe eight new Hylaeus species in Fiji (6), Micronesia (1), and French Polynesia (1) and discuss impressive dispersal events by this genus. These clades also double the number of Hylaeus dispersals out of Australia to from two to four. Our discovery highlights the severe impact of bee sampling methods on ecological interpretations, specifically that canopy sampling is needed to correctly assess forest bee diversity even where there is a very long record of sampling. It further highlights the potential for forests to host higher than anticipated diversity and conservation value. This should have broad methodological and regulatory impacts for land managers seeking to make choices about pollination services and diversity. The new species are Hylaeus (Euprosopoides) chuukensis Dorey, Davies, and Parslow 2023; H. (Prosopisteron) albaeus Dorey, Davies, and Parslow 2023; H. (P.) apertus Dorey, Davies, and Parslow 2023; H. (P.) aureaviridis Magnacca 2023; H. (P.) breviflavus Magnacca 2023; H. (P.) derectus Dorey, Davies, and Parslow 2023; H. (P.) navai Dorey, Davies, and Parslow 2023; and H. (P.) veli Dorey, Davies, and Parslow 2023.