Overview
The Megachilidae are recognised as a subfamily of Apidae in Michener (2000) and in the Lucid identification key on this website.
The following text is from Naumann (1991).
This world-wide family of small to very large, long-tongued bees is one of the most readily recognised in Australia. The large head is usually well developed in the genal and occipital regions. There are always 2 submarginal cells, with the 2nd as long, or nearly as long, as the 1st. The scopa (absent in
Coelioxys
) is on the abdominal sterna, not the legs.
Most Australian megachilids belong to the Megachilinae in which there are no pygidial or basitibial plates and the jugal lobe of the hind wing is short.
Chalicodoma
,
Coelioxys
and
Megachile
belong to the Megachilini, and
Anthidiellum
, restricted in Australia to the North and distinguished by having yellow integumental margins, belongs to the Anthidiini. Lithurginae, containing only
Lithurge
, are distinguished by certain primitive characteristics such as a long jugal lobe on the hind wing and remnants of a pygidial plate. Fideliinae (formerly Fideliidae) are not known from Australia.
No members of this family are social. Some are parasitic in the nests of other megachilids (in Australia,
Coelioxys
inhabits the nests of
Megachile
). Although some megachilids (especially
Lithurge
) possibly excavate new burrows, most use pre-existing burrows or hollows and a few (
Anthidiellum
and some
Chalicodoma
) build exposed nests on rocks or plants. Megachilinae are noteworthy for their use of foreign materials carried to the nests from other locations.
Megachile
makes its nests of neatly cut pieces of leaves (commonly rose leaves).
Chalicodoma
uses resin and/or masticated leaves and may incorporate soil, pebbles and other materials.
Lithurge
excavates branching burrows in dead wood and the cells in the blind ends of burrows are plugged with barricades of wood frass. Larval provisions of megachilids vary from a thick paste to a firm mass of pollen filling the distal part of the cell and the egg is deposited on the free surface (except in
Lithurge
which deposits it within or beneath the provisions (Houston 1971)). Mature larvae spin strong cocoons (not usually found in short-tongued bees).
Further information about the Apidae can be found in Melo & Goncalves 2005, Michener 1965, Michener 2000 and Naumann 1991.