Genus: Megachile Latreille, 1802
Subgenus: Eutricharaea Thomson, 1872
Common name: none
Megachile (Eutricharaea) are highly variable in color, but many species are small with black integument and pale apical hair bands on their terga (Michener 2007; Gonzalez 2008). Female Megachile (Eutricharaea) usually have white scopa except for on the apical sterna, but can have entirely golden or black scopa in rare cases (Michener 2007; Praz 2017). Megachile (Eutricharaea) range in body length from 5–16 mm (Michener 2007).
Megachile (Eutricharaea) is likely to be confused with Megachile (Eurymella) since they are both similar in size and both have a robust mandible with an enlarged apical tooth (Gonzalez 2008). Megachile (Eutricharaea) has a longer hind basitarsus than Megachile (Eurymella) and also has thickened basal setae on the tarsal claw of the hind leg (Praz 2017).
Megachile (Eutricharaea) are generalists that have been observed visiting Amaranthaceae, Apocynaceae, Asteraceae, Boraginaceae, Brassicaceae, Carduoideae, Chenopodiaceae, Cleomaceae, Convolvulaceae, Euphorbiaceae, Fabaceae, Hydrophyllaceae, Lamiaceae, Malvaceae, Nelumbonaceae, Plantaginaceae, Polygonaceae, Rutaceae, Tamaricaceae, Verbenaceae, and Zygophyllaceae (Westrich 1989; Raw 2007).
Megachile (Eutricharaea) nest in pre-existing cavities in soil, stems, beetle burrows, and under stones (Ferton 1914; Alqarni et al. 2014). They also occasionally dig burrows in sandy or hard soil (Westrich 1989; Mazzucco and Mazzucco 2007). Leaf discs and pieces of petals are used to construct their brood cells (Westrich 1989). Nest plugs are comprised of layers of leaf discs and mud mixed with saliva (Ferton 1914).
Megachile (Eutricharaea) is the most diverse subgenus of Megachile, and consists of approximately 240 species, nine of which have been introduced to the U.S. and several Caribbean islands (Michener 2007; Raw 2007; Gonzalez 2008; Moure et al. 2007; Rasmussen 2012).
Nine species of Megachile (Eutricharaea) have been introduced to the U.S. and Caribbean: Megachile apicalis, M. chlorura, M. concinna, M. derelictula, M. diligens, M. fullawayi, M.multidens, M. rotundata, and M. timberlakei (Raw 2007).
Megachile (Eutricharaea) chlorura, M. diligens, M. fullawayi, and M. timberlakei were introduced to Hawaii from Southeast Asia (Moore et al. 2008; Ascher and Pickering 2012; Rasmussen 2012). M. timberlakei was also introduced to the Galapagos Islands (Moure et al. 2007; Rasmussen 2012).
Megachile (Eutricharaea) concinna was likely accidentally introduced to the West Indies from Africa during the slave trade (Eickwort 1970; Raw 1985). It has since spread to the U.S. and the Dominican Republic (Moure et al. 2007; Rasmussen 2012).
Megachile (Eutricharaea) rotundata, the alfalfa-leafcutter bee, was intentionally introduced from their native Palearctic range to California in the 1940-50s to increase alfalfa pollination (Hurd 1954). They are now in widespread use by alfalfa seed producers in the U.S. (Hurd 1954). They have also been introduced to Chile, Argentina, Australia, and New Zealand for the same purpose (Raw 2007; Moure et al. 2007; Rasmussen 2012).
Megachile (Eutricharaea) range from southern Europe to southern Africa to eastern and southern Asia, Australia, and Oceania (Michener 2007). Nine species were introduced to the continental U.S., Hawaii, and several Caribbean islands, including the West Indies, the Dominican Republic, Barbados, and Jamaica (Michener 2007; Raw 2007; Moure et al. 2007; Rasmussen 2012).