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Megachile umatillensis (Mitchell, 1927)


Scientific Name: Megachile umatillensis (Mitchell, 1927)

Common Name: Umatilla Leafcutter Bee


Megachiloides umatillensis Mitchell, 1927: 118 [♂, ♀]

     Holotype ♂. USA, Washington, Camp Umatilla, 26 June 1882, by S. Henshaw [MCZ no. 15714]


Taxonomic notes: Megachile umatillensis Mitchell, 1927 is one of four known species of the M. oenotherae species group (i.e., Megachiloides s. str.), and the only one recorded from Canada (Sheffield 2013). This species group is defined by the extremely long tongue versus other Megachile in North America, and by the 3-dentate mandible of the female (Mitchell 1924; Bohart and Youssef 1972; Sheffield 2013), with a small, almost indistinguishable tooth next to the second tooth within the elongate interspace (Mitchell 1924; Sheffield 2013); Michener (2000, 2007) considered this a 4-dentate condition.

DNA Barcode Index Number (BIN):

Biology: Memebers of the M. oenotherae species group, including M. umatillensis, are oligoleges of Oenothera (Primulaceae) (Bohart and Youssef 1972; Sheffield 2013). The nesting biology was studied in detail by Bohart and Youssef (1972) who indicated that it nested on east-facing slopes in loose sparsely vegetated sand; at least 80% of the sand surface was exposed to direct sunlight. Nesting cells were constructed from flower petals of Oenothera sp., its floral host (Bohart and Youssef 1972; Sheffield 2013). Nests are parasitized by Coelioxys mesae Cockerell (Bohart and Yousseff 1972; as Coelioxys flagrata Baker)

Distribution in Canada: Sheffield et al. 2011 [BC]; Sheffield and Heron 2019 [BC].



Mitchell TB (1927) New megachilid bees. Psyche 34: 104-121.

Sheffield CS, Heron JM (2019) The bees of British Columbia (Hymenoptera: Apoidea, Apiformes). Journal of the Entomological Society of British Columbia 115: 44-85.

Sheffield CS, Ratti C, Packer L, Griswold T (2011) Leafcutter and mason bees of the genus Megachile Latreille (Hymenoptera: Megachilidae) in Canada and Alaska. Canadian Journal of Arthropod Identification 18: 1-107.

Sheffield CS (2013) A new species of Megachile Latreille subgenus Megachiloides (Hymenoptera, Megachilidae), ZooKeys 283: 43-58.

Bohart GE, Youssef NN (1972) Notes on the biology of Megachile (Megachiloides) umatillensis Mitchell (Hymenoptera: Megachilidae) and its parasites. Transactions of the Royal Entomological Society of London 124(1): 1-19.

Sociality: Solitary
Nesting: Ground
Pollen Specialization: Narrow Oligolecty
Wintering Stage: Mature Larva

Crop Preference: Not Available
Non Crop Preference: Oenothera sp., Oenothera pallida

Distribution: British Columbia
Ecozone: Western Interior Basin

Distribution Map