Genus: Rhodanthidium Isensee, 1927
Subgenera: Asianthidium, Meganthidium, Rhodanthidium
Common name: snail-shell bees
Rhodanthidium are moderate to large sized bees, ranging from 11–22 mm in body length. They have black integument with yellow or reddish-yellow maculations on their head, thorax, and abdomen (Michener 2007).
Rhodanthidium contains more than 13 species in three subgenera worldwide (Michener 2007); none are known to occur in the U.S. or Canada.
(modified from Michener 2007)
Rhodanthidium may be confused with Pseudoanthidium (Neanthidium), due to both genera having yellow, broken medial bands on their abdomens, but differ by the presence of arolia in Rhodanthidium (Michener 2007). Benanthis also share many features with some species of Rhodanthidium. They differ in that the T7 of Rhodanthidium males have 3 or 5 teeth and Benanthis have a bilobed T7. Female Benanthis have lateral teeth on S6, while Rhodanthidium lacks teeth on S6.
There are no known invasives.
Rhodanthidium visit plants within the families Asteraceae and Fabaceae (Proctor et al. 1996). Rhodanthidium siculum has been observed collecting pollen and nectar from flowers such as Galactites tomentosus, Centaurea sphaeocephala, Glebionis coronaria, and Lotus creticus (Erbar and Leins 2017).
Rhodanthidium are found from the Mediterranean area to southwestern and central Asia and central Europe (Michener 2007).