Coelioxys (Xerocoelioxys), 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 : 406

COELIOXYS (XEROCOELIOXYS) MITCHELL, 1973

Type species: Coelioxys edita Cresson, 1872 .

Diagnosis: Species in this subgenus are very similar to C. ( Coelioxys s.s.) spp., but can be differentiated by the pronotal lobe distinctly lamellate (Fig. 31) or carinate throughout, whereas in species of C. ( Coelioxys s.s.) the pronotal lobe is conspicuously rounded on its outer margin and weakly carinate on its inner margin ( Fig. 30 ). Another difference between species of these two subgenera is in the mesosomal pilosity, which is short, composed of subappressed or appressed hairs, forming marginal lines or spots on the mesoscutum in C. (Xerocoelioxys) spp. (Fig. 31), contrasting with the long and dense pubescence in species of C. ( Coelioxys s.s.) ( Fig. 30 ). The following combination of characteristics together with the two preceding ones separate species of C. (Xerocoelioxys) from all other subgenera. Mesoscutum coarsely and densely punctate, no interspaces linear to shorter than puncture diameter (as in Figs 83, 85 ); postgradular grooves of T 2 – T 3 complete, uninterrupted medially ( Fig. 24), and gradulus of T 2 bowed posteriorly.

Comments: Baker (1975) revised and keyed ten species in this subgenus. As a result of our phylogenies, C. serricaudata , previously placed in C. ( Coelioxys s.s.), is now regarded as belonging to C. (Xerocoelioxys). Also, considering the diagnostic characteristics of this subgenus, the other three North American species assigned by Baker (1975) to C. ( Coelioxys s.s.), Coelioxys hirsutissima Cockerell, 1912 , Coelioxys immaculata Cockerell, 1912 , and Coelioxys mitchelli Baker, 1975 , should be classified as C. (Xerocoelioxys). This subgenus is predominantly Nearctic but with some species reaching the Neotropical region of Mexico.

List of species: Coelioxys aperta Cresson, 1878 , Coelioxys bisoncornua Hill, 1936 , Coelioxys boharti Mitchell, 1962 , C. edita , Coelioxys galactiae Mitchell, 1962 , Coelioxys grindeliae Cockerell, 1900 , C. hirsutissima , C. immaculata , Coelioxys mesae Cockerell, 1921 , C. mitchelli , Coelioxys nodis Baker, 1975 , Coelioxys piercei Crawford, 1914 , C. serricaudata , C. soror , and Coelioxys soledadensis Cockerell, 1909 .

Six new subgenera are described as follows.

COELIOXYS (AUSTROCLEPTRIA) ROCHA- FILHO

Figures

Figures 30 and 31. Female, frontal view of pronotal lobe (outer margin indicated by red arrow): 30, Coelioxys sodalis; 31, Coelioxys grindeliae. Scale bars: 1.5 mm.

Figures 83–86. Female. 83, 84, Coelioxys rufescens: 83, dorsal view of mesoscutellum (for pilosity on anterior margin of mesoscutellum); 84, dorsal view of terga (for apical tergal fasciae). 85, 86, Coelioxys conoidea: 85, dorsal view of mesoscutellum (for pilosity on anterior margin of mesoscutellum); 86, dorsal view of terga (for apical tergal fasciae). Scale bars: 1.5 mm.