Osmia (Helicosmia) caerulescens (Linnaeus 1758)

County records: Calhoun, Cheboygan, Clinton, Ingham, Iosco, Jackson, Kalamazoo, Kent, Leelanau, Livingston, Manistee, Midland, Monroe, Montcalm, Oceana, Presque Isle, Sanilac, Schoolcraft, Shiawassee, Van Buren, Washtenaw, Wayne.

Notes. Probably exotic, based on lack of records from Alaska and, until recently, from western Canada and the Pacific Northwest (now well established in, e.g., the Seattle vicinity, as shown by records on http://bugguide.net) but historically was restricted to Eastern North America. A relatively early Idaho record was considered “probably adventive” by Hurd (1979). Cavity-nesting described from New York (Krombein 1967) and Wisconsin (Medler 1967a). Its potential as an alfalfa pollinator has been studied in France (Tasei & Picart 1972).