Anthidiellum (Ranthidiellum), Ranthidiellum Pasteels, 1969

Nalinrachatakan, Pakorn, Traiyasut, Prapun, Khongnak, Anupong, Muangkam, Manop, Ascher, John S. & Warrit, Natapot, 2021, The resin bee subgenus Ranthidiellum in Thailand (Megachilidae, Anthidiini): nesting biology, cleptoparasitism by Stelis, and new species, ZooKeys 1031, pp. 161-182 : 161

Subgenus Ranthidiellum Pasteels, 1969

Anthidiellum (Ranthidiellum) Pasteels, 1969: 48. Type species: Protoanthidium rufomaculatum Cameron, 1902, by original designation. [other aspects of type designation discussed in Michener and Griswold (1994)]

Anthidiellum (Rhanthidiellum) Pasteels, 1972: 102, unjustified emendation of Ranthidiellum Pasteels, 1969.

Diagnosis.

Moderate size (around 7-10 mm); clypeus subtriangular as frontoclypeal suture curved upwards; subantennal suture arcuate; eyes convergent ventrally; preoccipital margin round, not carinate; pronotal lobe raised, extended, and lamellated; omaular carina complete to the ventral region of thorax; scutellum and axilla large, margin translucent; propodeum without dimple; abdomen appears oval, shiny with reddish, orangish, or ferruginous extended.

Female: mandible apically broad, about 1.5 × wider than base, with four small teeth; hind basitarsus enlarged; abdomen oval shaped, longer than wide, gradually smaller from third segment; T6 margin subtruncate, shield-like; S6 simple.

Male: mandible tridentate, apex not wide as in female; T6 with apical transverse border; T7 short with median spine; S4 marginally with transparent membrane; S5 indented with black comb; gonoforceps bifid.