Subgenus Dialictus Robertson, 1902

Paralictus Robertson 1901: 229 . Type species: Halictus cephalictus Robertson, 1892, by original designation. Opinion 1882 (ICZN 1997)

Dialictus Robertson 1902a: 48 . Type species: Halictus anomalus Robertson, 1892, by original designation and monotypy. Chloralictus Robertson 1902b: 248 . Type species: Halictus cressonii Robertson, 1890, by original designation.

Halictus (Gastrolictus) Ducke 1902: 102 . Type species: Halictus osmioides Ducke, 1902, by monotypy.

Halictomorpha Schrottky 1911: 81 . Type species: Halictomorpha phaedra Schrottky, 1911, by original designation. Rhynchalictus Moure 1947: 5 . Type species: Rhynchalictus rostratus Moure, 1947, by original designation.

Halictus (Smeathhalictus) Warncke 1975: 88 . Type species: Melitta smeathmanella Kirby, 1802, by original designation. Evylaeus (Viridihalictus) Pesenko 2007a: 26 . Type species: Halictus viridis Brullé, 1840, by original designation. Evylaeus (Glauchalictus) Pesenko 2007a: 26 . Type species: Halictus problematicus Blüthgen, 1923, by original designation. Evylaeus (Virenshalictus) Pesenko 2007a: 26 . Type species: Halictus virens Erichson, 1835, by original designation. Evylaeus (Loethalictus) Pesenko 2007a: 26 . Type species: Halictus loetus Brullé, 1840, by original designation.

Evylaeus (Aerathalictus) Pesenko 2007a: 27 . Type species: Melitta aerata Kirby, 1802, by original designation.

Diagnosis. This subgenus is separated from other subgenera in the Hemihalictus series occurring in eastern Asia by a combination of head and mesosoma with brilliant or dull green-metallic luster (Figs 1 C, 2A) and mesepisternum with shallow PP (Fig. 2 D) or reticulate PP. In eastern Asia, the apristum group belonging to L. ( Sphecodogastra) has green-metallic luster on head and mesosoma in female. But, the members of this group can be separated from L. ( Dialictus) in having the mesepisternum coarse reticulate-rugulose (Fig. 2 C), the posterior surface of propodeum with complete lateral carina such as Fig. 3 B, and the inner hind tibial spur with fine serration (Murao et al. 2015a). Comments. Palearctic species is classified into 6 species groups as defined by Pesenko (2007a): aeratum group (Ebmer 1976b), atroglaucum group (Ebmer 2002), loetum group, smeathmanellum group, viride group (Ebmer 1993), and virens group (treated in Pesenko 2007a, as Evylaeus (Aerathalictus), E. (Glauchalictus), E. (Loethalictus), E. (Smeathhalictus), E. (Viridihalictus), and E. (Virenshalictus, respectively). Three groups of them occur in the Korean Peninsula: aeratum, atroglaucum and smeathmanellum.