Bombus (Psithyrus) variabilis (Cresson, 1872)

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, Zootaxa 5304 (1), pp. 1-95 : 30

Bombus (Psithyrus) variabilis (Cresson, 1872)

Counties: Rock.

Comments: This globally rare and declining species is known in Minnesota from a single female from the southwesternmost corner of the state, though it was likely more widespread in Minnesota since it has also been recorded from Fargo, North Dakota ( Stevens 1948) and Brookings County, South Dakota ( Martens et al. 2022). Bombus variabilis is potentially extinct or extirpated from the United States. The most recent records from the US that we have personally confirmed are from over 20 years ago in 1998 and 1999 (Missouri, St. Clair Co.: Wah-Kon-Tah Prairie: 1 ♁, 20 Sep 1998, J. Silkel leg., determined by M. Arduser; Missouri, Scott Co.: Hwys. H and C intersection, northwest corner, wetland on the Mississippi River alluvial plain: 1 ♀, 26 Aug 1999, at Asclepias incarnata flowers, Arduser coll., determined by M. Arduser). This species is IUCN-listed as critically endangered ( Hatfield et al. 2015) and recently it had a USFWS positive 90-day finding ( U.S. Fish and Wildlife Service, 2022) and awaits a listing decision.

Minnesota material examined: Rock Co.: Mound Springs State Park [now Blue Mounds State Park]: 1 ♀, 15 Sep 1948, H.E. Milliron leg., determined by R. Fischer, confirmed by J. Gardner and Z. Portman .

Subgenus Pyrobombus Dalla Torre