Pseudoanthidium, Friese, 1898

Kasparek, Max, 2021, The bee genus Pseudoanthidium: revision of the subgenus Exanthidium with the description of a new species (Apoidea: Megachilidae), Fragmenta entomologica 53 (2), pp. 333-346 : 334

Pseudoanthidium Subgenus Exanthidium ( Pasteels, 1969)

Exanthidium was erected by Pasteels (1969) with eximium Giraud, 1863 ( = excisum Mocsáry, 1884 ) as type species. Additionally to the type species, he included two species, E. enslini Alfken, 1928 and E. wahrmanicum Mavromoustakis, 1953 . Later, he described E. guichardi Pasteels, 1980 which he also included in this genus ( Pasteels 1980). Warncke (1980) treated Exanthidium as subgenus of Anthidium and listed additionally Anthidium pictipes Morawitz, 1894 , but without including this taxon in his key and without integrating it into his consecutive numbering. Michener & Griswold (1994) and Michener (2007) proposed recognising Pseudoanthidium Friese, 1898 on the genus level, and Exanthidium herewith as one of its subgenera.

The characterisation of Exanthidium by coherent traits valid for all taxa remains challenging. According to Michener (2007), the character traits of the female of Exanthidium include a small, midapical, marginal lobe on the apical margin of T5. Such a lobe, however, was observed only in P. wahrmanicum , not in P. enslini and P. eximium (the females of the other species are unknown). A broadly rounded or truncate, somewhat denticulate apex with a pair of small, shining, depressed median lobes on either side of a notch of T6 was mentioned as another character trait by Michener (2007). These lobes were, however, observed only in P. enslini and P. eximium , not in P. wahrmanicum (the females of the other species are unknown). Litman et al. (2016) additionally mentioned a lateral spine on T6 as a trait characterising Exanthidium , but such a spine was observed only in P. enslini and P. eximium , not in P. wahrmanicum and P. deserticolum sp. n. The morphological features common to all members of the genus Exanthidium thus seem to be less than hitherto assumed.

Exanthidium is understood here as a group of anthidiine bees whose females are clearly distinct from all other Palaearctic members of Pseudoanthidium by an excavated, strongly concave T6. The clypeus is almost flat, the apex slightly curved inward and covered with hair (not protruding and fully exposed as e.g. in Royanthidium ). The male can be characterised by its long (significantly longer than T6), protruding and deeply bilobed T7, and the absence of combs on the sterna.

The distribution of Exanthidium extends from the East Atlantic coast ( Portugal) to Central Asia ( Tajikistan). Michener (2007) also mentions Sudan. It is not known on what basis this statement was made. Anthidium brevithorace Warncke, 1982 shares in the male with Exanthidium the long, protruding T7, but has been assigned to the subgenus Turkanthidium by Warncke (1982) and is not treated here.