Review of the North American fauna of Drymeia Meigen (Diptera, Muscidae) and evaluation of DNA barcodes for species-level identification in the genus

The North American fauna of Drymeia Meigen was studied. Four new species are described (Drymeia huckettisp. nov., Drymeia pontisp. nov., Drymeia vockerothisp. nov., Drymeia woodorumsp. nov.), and three new synonymies are proposed: Drymeia amnicola (Huckett, 1966) (= Drymeia rivalis (Huckett, 1966), syn. nov.); Drymeia glacialis (Rondani, 1866) (= Drymeia alpicola (Rondani, 1871), syn. nov.); and Drymeia spinitarsis (Aldrich, 1918) (= Drymeia longiseta Sorokina & Pont, 2015, syn. nov.). An annotated checklist, DNA barcodes (when available), and keys for each sex of the 24 named species of North American Drymeia are provided. The utility of DNA barcodes for the identification of Drymeia species across a wide geographical range was explored using sequences from five countries. A match between morphology and DNA barcodes was found for 71% (22/31) of species studied (including three unnamed taxa). The remaining nine species clustered into two groups of taxa with very little interspecific variation within clusters (groups of two and seven species). Caution is advised against using DNA barcoding as the only determination tool for Drymeia material without prior knowledge of its limitations for certain species groups.