DNA Barcoding for Identifying Native Bee Species

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The Challenge: Traditionally, bee identification has relied on taxonomic methods centered on descriptions of morphological differences between species. However, for many species, separate keys are required for identifying adult males and females and immature life stages. These keys are commonly unavailable. The lack of distinguishing morphological characters useful for separating closely related species is a common problem in many bee species, reducing the effectiveness and completeness of bee diversity surveys and general biological studies of bees.

The Science: DNA Barcoding, based on sequence variation between taxa in the cytochrome c oxidase subunit 1 (COI) of mitochondrial DNA or other loci, has provided an alternative, genetically-based methodology for distinguishing specimens. The application of Next-Generation Sequencing (NGS) technologies to DNA Barcoding has permitted the sequencing of many more samples at one time, at lower cost, and increased sequencing depth per specimen. This project is using NGS to generate DNA Barcode information to assist in the resolution of multiple closely allied species that are of interest to population studies conducted by the USGS.

The Future: Multiple pairs of taxa have been identified as targets for this project. Each of these pairs presents difficulties with resolution based on morphology alone and will be sequenced to resolve or confirm species identities. The initial work will focus on Halictus ligatus and Halictus poeyi. These bees are so similar morphologically that differentiation between them is generally based on geographic range. This project supports the National Pollinator Health Strategy to promote the health of native bees, by providing tools that improve bee identification and understanding of community structure and habitat requirements, and provides data for inventories of native bees.