Coelioxys (Synocoelioxys), MITCHELL, 1973

Rocha Filho, Léo Correia Da & Packer, Laurence, 2017, Phylogeny of the cleptoparasitic Megachilini genera Coelioxys and Radoszkowskiana, with the description of six new subgenera in Coelioxys (Hymenoptera: Megachilidae), Zoological Journal of the Linnean Society 180 (2), pp. 354-413 : 405

COELIOXYS (SYNOCOELIOXYS) MITCHELL, 1973

Type species: Coelioxys texana Cresson, 1872 .

Diagnosis: This is the only Coelioxys subgenus and perhaps the only members of the Megachilini in which the male S7 is bilobed ( Fig. 94H) rather than divided into two small sclerites ( Baker, 1975: fig. 26D). Some characteristics such as the scale-like pubescence in parts of the body ( Fig. 32 ), the inner ramus of pretarsal claws in females acute ( Fig. 36 ), and apicodorsal processes of T 6 in males forked ( Fig. 34 ) are shared only with species of the Old World subgenus C. (Allocoelioxys). Species belonging to C. (Synocoelioxys) are characterized by the following combination of characteristics that separates them from all other subgenera. Median ocellus surrounded by a swollen and nearly impunctate area ( Fig. 32 ). Female: lateral margins of T 6 apex with long thick hairs forming an inconspicuous fringe ( Fig. 33 ); S6 rounded or elliptical, not notched and straight ( Fig. 33 ), not flexed downwards. Male: T 6 apicodorsal processes forked, with processes flattened, pointed, and irregular, almost forming a crenulate plate ( Fig. 34 ), and T 7 exposed, with a long median tooth-like process medially ( Baker, 1975: fig. 13A).

Comments: Species of C. (Synocoelioxys) are primarily Nearctic; five of them were revised and keyed by Baker (1975); another two, Coelioxys toltecoides Cockerell, 1923 from Mexico and Coelioxys tegularis Cresson, 1869 from Cuba, are also assigned to the subgenus ( Ascher & Pickering, 2015).

List of species: Coelioxys alternata Say, 1837 , Coelioxys apacheorum Cockerell, 1900 , Coelioxys erysimi Cockerell, 1912 , Coelioxys hunteri Crawford, 1914 , C. tegularis *, C. texana , and C. toltecoides .

Figures

Figures 32–34. 32, 33, female. 32, Coelioxys texana: dorsal view of mid ocellus. 33, Coelioxys alternata: dorsal view of T6 and S6. 34, male, Coelioxys alternata: dorsal view of T6 (dorsal process indicated by red arrow). Scale bars: 1.5 mm.

Figures 35–37. 35, 36, female. 35, Coelioxys albolineata: dorsal view of mesoscutellum (for axilla length). 36, Coelioxys froggatti: lateral view of pretarsal claws (inner rami indicated by black arrows). 37, male, Coelioxys reginae: lateral view of head (for genal excavation). Scale bars: 1.5 mm.