Numbers
Arnett, p. 604, lists 682 spp.
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Nearctica lists 18 genera.
Identification
Most are of moderate size and stout bodies.
"Front wings with two submarginal cells, abdomen with pollen-collecting basket ventrally, absent in parasitic species".
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OVERVIEW OF GENERA
♀ 
♂Habitat
Typically fields with flowers, etc.
Food
Adults visit flowers for nectar.
Life Cycle
Most are leaf-cutters, nesting in ground, in cavities, wood. Tunnels are bored in wood or in the ground. Cell is provisioned with pollen (and nectar?), an egg laid, and cell is sealed over with circular pieces of leaves that fit tightly into cavity. A few (
Stelis,
Coelioxys) are
(clepto)parasitic, laying their eggs in the nests of other members of this family.
Print References
Lutz, 3rd ed., plate 70, illustrates several genera
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Borror and White, pp. 358-359
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Swan and Papp, p. 577, fig. 1243, illustrates
Megachile.
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Arnett and Jacques, #302, illustrates
Megachile.
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Milne, pp. 857-859, illustrates
Megachile, Osmia, Trachusa; describes life histories.
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