Coelioxys (Boreocoelioxys), 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 : 393

COELIOXYS (BOREOCOELIOXYS) MITCHELL, 1973

Type species: Coelioxys rufitarsis Smith, 1854 .

Diagnosis: Species in this subgenus are characterized by the combination of long, dense pubescence on head and mesosoma never accompanied by short, scale-like hairs, and with postgradular grooves of T 2 and T 3 complete ( Fig. 24). This combination is also observed in all species of C. ( Coelioxys s.s.). In C. (Boreocoelioxys) females, however, the S6 is elongate, gradually tapering towards the apex and conspicuously notched subapically [ Fig. 26 ; constricted subapically and never notched in both C. ( Coelioxys s.s.) ( Fig. 28 ) and C. (Xerocoelioxys) females ( Fig. 14)]. In C. (Boreocoelioxys) males the postgradular grooves of T 2 have a sublateral, slender fovea on each side ( Fig. 27 ), whereas in males of C. ( Coelioxys s.s.) and C. (Xerocoelioxys) spp. the postgradular area of T 2 is never foveate, but instead with sublateral, slender, densely punctate area on each side ( Fig. 29 ), or unmodified.

Comments: This subgenus has been regarded as mainly Holarctic ( Michener, 2007), but as such it is very weakly supported (see Results and Discussion and Fig. 1). In contrast, the New World clade is well supported. In light of this, C. (Boreocoelioxys) is now defined as comprising only the New World species, among which the Nearctic species and Coelioxys oaxacana Baker, 1975 were revised and keyed by Baker (1975). There are two additional species from the Neotropics: Coelioxys sannicolarensis Genaro, 2001 and Coelioxys schmidti Friese, 1917 . The following species are being transferred to other subgenera according to the phylogenetic results: C. alata , C. funeraria , and C. rufescens . The other species from the Palaeartic region that were previously assigned to C. (Boreocoelioxys) ( Ascher & Pickering, 2015) may belong to C. (Paracoelioxys) or to the new subgenus described herein to encompass C. rufescens ; however, it is important to highlight that a revision of those species is necessary in order to establish an accurate classification for this fauna.

List of species: Coelioxys banksi Crawford, 1914 , Coelioxys insita Cresson, 1872 , Coelioxys moesta Cresson, 1864 , Coelioxys novomexicana Cockerell, 1909 , C. oaxacana , C. octodentata , Coelioxys porterae Cockerell, 1900 , Coelioxys pratti Crawford, 1914 , C. rufitarsis , Coelioxys salinaria Cockerell, 1925 , C. sannicolarensis *, C. sayi , and C. schmidti *. The Neotropical species Coelioxys auripes Friese, 1921 also seems to belong to this subgenus given the complete postgradular grooves of T 2 and T 3.

Figures

Figures 26–29. 26, female, Coelioxys porterae: dorsal view of T6 and S6. 27, male, Coelioxys sayi: dorsal view of T2 (fovea indicated by red arrow). 28, female, Coelioxys quadridentata, dorsal view of T6 and S6. 29, male, Coelioxys sodalis: dorsal view of T2 (punctate area indicated by red arrow). Scale bars: 1.5 mm.