Hylaeus (Hylaeus) mesillae (Cockerell, 1896) Counties: Aitkin, Anoka, Becker, Beltrami, Benton, Big Stone, Brown, Carver, Cass, Chippewa, Chisago, Clay, Clearwater, Cottonwood, Crow Wing, Dodge, Douglas, Faribault, Freeborn, Goodhue, Grant, Hennepin, Houston, Hubbard, Isanti, Itasca, Jackson, Kanabec, Kandiyohi, Kittson, Koochiching, Lac qui Parle, Lake, Lyon, Mahnomen, Marshall, Martin, McLeod, Meeker, Mille Lacs, Morrison, Murray, Nobles, Norman, Olmsted, Otter Tail, Pennington, Pine, Pipestone, Polk, Pope, Ramsey, Red Lake, Redwood, Renville, Rice, Rock, Roseau, Saint Louis, Scott, Sherburne, Stearns, Steele, Stevens, Swift, Traverse, Wabasha, Washington, Watonwan, Wilkin, Winona, Wright, Yellow Medicine. Comments: What has traditionally been called “ Hylaeus mesillae ” or “ Hylaeus mesillae cressoni ” is a species complex containing an estimated three taxa in Minnesota. This complex may include specimens of the similar species H. rudbeckiae, which has the females separated by size alone (Snelling 1970), but the complex does not include H. saniculae, which is morphologically distinct. That H. mesillae is a species complex is consistent with Oram (2018), who also found evidence that H. mesillae is a species complex in Canada containing six distinct DNA barcodes. As a result, most recent collections are referred to as “ Hylaeus ‘ mesillae group’” (e.g. Lane et al. 2020, 2022). These taxonomic issues must be solved by a revision of this species.

Published as part of Portman, Zachary M., Gardner, Joel, Lane, Ian G., Gerjets, Nicole, Petersen, Jessica D., Ascher, John S., Arduser, Mike, Evans, Elaine C., Boyd, Crystal, Thomson, Robin & Cariveau, Daniel P., 2023, A checklist of the bees (Hymenoptera: Apoidea) of Minnesota, pp. 1-95 in Zootaxa 5304 (1) on page 46, DOI: 10.11646/zootaxa.5304.1.1, http://zenodo.org/record/8048569