Plesianthidium Cameron

Plesianthidium Cameron, 1905: 256 . Type species: Plesianthidium fulvopilosum Cameron, 1905, by original designation.

Plesianthidium (Plesianthidium): Michener & Griswold 1994: 301 –319.

Dianthidium (Spinanthidium) Mavromoustakis, 1951: 977 . Type species Anthidium trachusiforme Friese, 1913, by original designation.

Spinanthidium: Pasteels 1969: 10 –60.

Plesianthidium (Spinanthidium): Michener & Griswold 1994: 301 –319.

Carinanthidium Pasteels, 1969: 42. Type species: Megachile (Chalicodoma) cariniventris Friese, 1904, by original designation.

Plesianthidium (Carinanthidium): Michener & Griswold 1994: 301 –319.

Spinanthidium (Spinanthidiellum) Pasteels, 1969: 59 . Type species: Anthidium volkmanni Friese, 1909, by original designation.

Plesianthidium (Spinanthidiellum): Michener & Griswold 1994: 301 –319.

There are twelve species in Plesianthidium . Two occur in monotypic subgenera: Plesianthidium . (Carinanthidium) cariniventre (Friese, 1904), a large black bee the female of which can be identified by a mediolongitudinal carina on S6 and the male by a spinose hind trochanter, and Plesianthidium (Plesianthidium) fulvopilosum Cameron, a large orange bee in which the posteromedial spine on the male T7 is reduced, as in the male of P. (Carinanthidium). Plesianthidium (Spinanthidiellum) has a distinct pre-occipital carina dorsally. It comprises three species; P. (Sl.) volkmanni (Friese, 1909), P. (Sl.) rufocaudatum (Friese, 1909) and P. (Sl.) haematurum (Cockerell, 1932) . Plesianthidium (Spinanthidium), on the other hand, has a rounded preoccipital region, two-segmented maxillary palpus, and the male T7 is tridentate with three large posteriorly directed spines. It is the most diverse subgenus, with seven species. Michener (2007) provided a key to the subgenera of this genus.

Diagnosis. Plesianthidium can be recognized by the combination of straight subantennal sutures, and a distinctly open and shiny scutum-scutellar suture. Additional characters for females include head with completely black integument, a black mesosoma, mandibles spatulate (expanded apically, with a few teeth on outer distal edge and a flattened blade often with indistinct teeth) with three to five teeth, and cylindrical hind basitarsi. Male mandibles are 3-toothed and T6 is extended posteromedially.

Plesianthidium primarily occurs in the semi-desert, winter rainfall region of southern Africa. Willowmore, from which three species are recorded (P. cariniventre, P. volkmanni and P. rufocaudatum) is semi-desert but mostly with summer rain. Two doubtful distribution records exist for P. cariniventre: Shilouvane, South Africa, and Rikatla, Mozambique. They are both mostly summer rain, savannah.