Key to male metallic Lasioglossum (Dialictus) of eastern North America

1. Tegula ovoid with at most weak posterior angle, usually obscurely punctate (Fig. 7 B)................................ 2

- Tegula enlarged with strong posterior angle, distinctly punctate (Fig. 7 A) (except obscurely punctate in L. surianae; Fig. 203)................................................................................................... 92

2. Mesoscutal punctures sparse between parapsidal lines, interspaces greater than puncture diameter (i> d)................ 3

- Mesoscutal punctures dense between parapsidal lines, interspaces no greater than puncture diameter (i <d)............. 84

3. Clypeus with apical margin brown or reddish brown.......................................................... 4

- Clypeus with apical margin yellow....................................................................... 70 4. Pronotal ridge broadly rounded, not forming sharp angle...................................................... 5 - Pronotal ridge carinate or forming sharp angle.............................................................. 63 5. Forewing submarginal cells three (vein 1rs-m present) (Fig. 5 A)................................................ 6 - Forewing submarginal cells two (vein 1rs-m absent) (Fig. 5 B)................................................. 62 6. Mesepisternum impunctate.............................................................................. 7 - Mesepisternum distinctly punctate....................................................................... 41 7. Mesoscutal punctures fine to moderately coarse; mesepisternum rugulose or weakly rugose........................... 8 - Mesoscutal punctures very coarse; mesepisternum strongly rugose or reticulate................................... 37 8. T2 apical impressed areas impunctate or at most a few basal punctures (Fig. 31 B).................................. 9 - T2 apical impressed areas distinctly punctate (Fig. 31 A)...................................................... 31 9. Mesoscutal punctures dense laterad of parapsidal line (i≤d) (Fig. 12 B)........................................... 10 - Mesoscutal punctures sparse laterad of parapsidal line (i=1–3d) (Fig. 12 A)....................................... 28 10. Mesoscutum dull due to strong microsculpture including on submedial and posterior portions........................ 11 - Mesoscutum polished due to weak microsculpture at least on submedial and posterior portions....................... 21 11. Head elongate (length/width ratio> 1.06)................................................................. 12 - Head shorter (length/width ratio <1.03)................................................................... 17 12. Head very long (length/width ratio> 1.09); metapostnotal rugae weak, not reaching posterior margin.................. 13