Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Family Megachilidae - Leafcutter, Mason, and Resin Bees, and allies

Large megachilid - Megachile pugnata - female megachilid bee - Megachile Small Bee - Osmia caerulescens Native Bee - Megachile Megachilidae - Osmia Unknown bee - Megachile Bee on Ironweed - Megachile Anthidium oblongatum - female
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon (Aculeata - Ants, Bees and Stinging Wasps)
No Taxon (Anthophila (Apoidea) - Bees)
Family Megachilidae (Leafcutter, Mason, and Resin Bees, and allies)
Explanation of Names
From genus Megachile Latreille
>630 spp. in 18 genera of 4 tribes and 2 subfamilies in our area, ~4,100 spp. in ~80 genera of 11 tribes and 4 subfamilies worldwide(1)
Overview of our fauna (* –taxa not yet in the guide)
Family Megachilidae
Subfamily Megachilinae
6-18 mm
Most are of moderate size and stout bodies. Front wings with two submarginal cells, abdomen with pollen-collecting basket ventrally, absent in parasitic species.(2)
Guide to eastern genera in

Generally appear more cigar shaped than other bees. There are 2 submarginal cells on their wings with the 2nd one noticeably larger as in this photo or with arrows drawn to this on this website Insects of Alberta

Labrum is longer than it is wide. Females have scopa on underside of abdomens rather than on legs – no other bee has this. A good photo of this




Genus Lithurgus- Lithurge




worldwide and throughout NA(1)
Life Cycle
Some 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, clay or other materials 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
Chaetodactylus mite parasites of Megachilidae (O'Connor & Klimov 2009-2012)
Internet References
Fact sheet (Serrano 2005-2014)(6)