Belongs within: Anthophila.
Contains: Megachilinae.
The Megachilidae are a group of long-tongued bees generally characterised by a well-developed scopa (array of long hairs) on the metasomal sterna. The plesiomorphic scopa on the hind legs of other bee families is reduced in most megachilids; members of the basal subfamily Fideliinae retain a scopa-like array of setae on the hind legs. The subfamilies Lithurginae and Megachilinae are also characterised by a subantennal suture that meets the outer margin of the antennal socket (Engel 2001). Lithurginae retain the pygidial and metabasitibial plates, though both may be reduced, and the first metasomal tergite is short and flat. The fossil Baltic amber species Protolithurgus ditomeus differs from modern lithurgines in its relatively short glossa, bidentate mandibles, and lack of metatibial spicules (Engel 2001).
Characters (Engel 2001): Labrum broadly articulated to clypeus, frequently longer than wide. Single subantennal suture; suture meets lower margin of antennal socket in Fideliinae, meets outer margin of antennal socket in Megachilinae and Lithurginae. Facial foveae absent. Lower lateral margins of clypeus not bent posteriorly on either side of labrum. Flabellum present; glossa acute; labial palpus with first two segments flattened, sheath-like, and elongate; submentum strongly V-shaped and sclerotized, submental arms articulating with cardines slightly above cardo-stipital articulations. Galeal comb absent; stipital comb and concavity present; basistiptial process elongate. Pre-episternal groove absent. Mesocoxa entirely exposed. Metabasitibial plate variable (present in Protolithurgini and some Lithurgini along posterior margin; absent in Fideliinae and Megachilinae). Jugal lobe short. Metasomal scopa present (in nonparasitic females). Metapostnotum setose. Pygidial plate and fimbria of female present in Fideliinae and Lithurginae, absent in Megachilinae.
<==Megachilidae [Fideliidae, Megachiliformes]
| i. s.: Anthidioma chalicodomoidesGGE19
| Gnathanthidium prionognathumGGE19
| Indanthidium crenulaticaudaGGE19
| Xenoheriades micheneriGGE19
| Xenostelis polychromaGGE19
|--FideliinaeGGE19
| |--Neofidelia [Neofideliini]GGE19
| | `--N. profuga Moure & Michener 1955CSD10
| `--Fidelia [Fideliini]GGE19
| |--F. (Parafidelia) pallidulaGGE19
| `--+--F. (Fidelia) villosaGGE19
| `--+--F. (Fideliana) braunsianaGGE19
| `--F. major (Friese 1911)GGE19, CSD10
`--+--MegachilinaeGGE19
`--+--Pararhophites [Pararhophitinae, Pararhophitini]GGE19
| |--P. orobinusBD17
| `--P. quadratus (Friese 1898)CSD10
`--LithurginaeGGE19
|--Protolithurgus Engel 2001 [Protolithurgini]E01
| `--*P. ditomeus Engel 2001E01
`--Lithurgini [Trichothurgini]CSD10
| i. s.: AustrothurgusH18
| |--A. cognatus (Smith 1868)H18, M65 [=Lithurgus cognatusH18]
| `--A. rubricatus (Smith 1853)H18, M65 [=Lithurgus rubricatusH18]
|--+--MicrothurgeCSD10
| | |--M. corumbaeCSD10
| | `--M. frieseiGGE19
| `--TrichothurgusCSD10 [incl. LithurgommaE01]
| |--T. aterrimusGGE19
| |--T. herbsti (Friese 1905)CSD10
| `--T. wagenknechtiGGE19
`--Lithurgus Latreille 1825PK17, M65 [=LithurgeM65]
| i. s.: L. adamiticus (Heer 1865)E01
| L. andrewsi Cockerell 1909 [=Lithurge andrewsi]JG19
| L. chrysurusPK17
| L. echinocacti Cockerell 1898CSD10
| L. fuscipennisR35
| L. pullatusBD17
|--L. (Lithurgus)M65
| |--*L. (L.) cornutus (Fabricius 1787) [=Andrena cornuta, *Lithurge cornutus]M65
| |--L. (L.) albofimbriatus Sichel 1867M65
| |--L. (L.) atratiformis Cockerell 1905M65
| |--L. (L.) atratus Smith 1853M65
| |--L. (L.) bractipes Perkins & Cheesman 1928M65
| |--L. (L.) dentipes Smith 1853M65
| |--L. (L.) fortis Cockerell 1929M65
| |--L. (L.) froggatti Cockerell 1914M65
| |--L. (L.) huberiM65
| |--L. (L.) nigerrimus Krombein 1949M65
| `--L. (L.) scabrosus (Smith 1859) [=Megachile scabrosa]M65
`--L. (Lithurgopsis) apicalisGGE19
*Type species of generic name indicated
References
[BD17] Branstetter, M. G., B. N. Danforth, J. P. Pitts, B. C. Faircloth, P. S. Ward, M. L. Buffington, M. W. Gates, R. R. Kula & S. G. Brady. 2017. Phylogenomic insights into the evolution of stinging wasps and the origins of ants and bees. Current Biology 27: 1019–1025.
[CSD10] Cardinal, S., J. Straka & B. N. Danforth. 2010. Comprehensive phylogeny of apid bees reveals the evolutionary origins and antiquity of cleptoparasitism. Proceedings of the National Academy of Sciences of the USA 107 (37): 16207–16211.
[E01] Engel, M. S. 2001. A monograph of the Baltic amber bees and evolution of the Apoidea (Hymenoptera). Bulletin of the American Museum of Natural History 259: 1–192.
[GGE19] Gonzalez, V. H., G. T. Gustafson & M. S. Engel. 2019. Morphological phylogeny of Megachilini and the evolution of leaf-cutter behavior in bees (Hymenoptera: Megachilidae). Journal of Melittology 85: 1–123.
[H18] Houston, T. 2018. A Guide to Native Bees of Australia. CSIRO Publishing.
[JG19] James, D. J., P. T. Green, W. F. Humphreys & J. C. Z. Woinarski. 2019. Endemic species of Christmas Island, Indian Ocean. Records of the Western Australian Museum 34 (2): 55–114.
[M65] Michener, C. D. 1965. A classification of the bees of the Australian and South Pacific regions. Bulletin of the American Museum of Natural History 130: 1–362.
[PK17] Peters, R. S., L. Krogmann, C. Mayer, A. Donath, S. Gunkel, K. Meusemann, A. Kozlov, L. Podsiadlowski, M. Petersen, R. Lanfear, P. A. Diez, J. Heraty, K. M. Kjer, S. Klopfstein, R. Meier, C. Polidori, T. Schmitt, S. Liu, X. Zhou, T. Wappler, J. Rust, B. Misof & O. Niehuis. 2017. Evolutionary history of the Hymenoptera. Current Biology 27 (7): 1013–1018.
[R35] Rayment, T. 1935. A Cluster of Bees: Sixty essays on the life-histories of Australian bees, with specific descriptions of over 100 new species. Endeavour Press: Sydney.