Redefining the Geographic Distribution of Two Cryptic Halictus (Hymenoptera: Halictidae) Species in the Eastern United States.

Incomplete characterization of cryptic species complexes in pollinator communities can limit our understanding of ecosystem function, population dynamics, effects of environmental perturbations, and conservation planning. Molecular tools to distinguish morphologically indistinguishable bee species are therefore necessary but require refinement and validation to make robust inferences. Here we present newly developed primers and demonstrate their successful use for identification of two cryptic bee species, Halictus ligatus and Halictus poeyi, with overlapping ranges in the mid-Atlantic USA. We found that H. ligatus is present at higher elevations while H. poeyi is present at lower elevations, with both species present at three sample sites in central North Carolina, USA. The data generated in this study was combined with publicly available sequence data and analyzed to make inferences about the species ranges of these two bees in the Western Hemisphere. These clarified species distributions help us better understand local pollinator communities, associated habitat features, and abiotic conditions amenable to each, as well as provide insights into patterns related to their speciation.