Lasioglossum (Dialictus)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 26

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

Figures

FIGURE 5. Forewings of female Lasioglossum subgenus Dialictus. (A) Typical forewing with three submarginal cells. Pterostigma (pt), basal vein (b), arrows indicate weakened veins. (B) Forewing with two submarginal cells. Arrows indicate weakened veins. (From Gibbs 2010 b).

FIGURE 7. Tegula (A) punctate, enlarged, punctate with posterior angle (B) ovoid, without posterior angle (L. nymphaearum). (From Gibbs 2010 b).

FIGURE 12. Mesoscutal punctation on lateral portion of disc (A) sparse (B) dense. (From Gibbs 2010 b).

FIGURE 203. Lasioglossum surianae (Mitchell) male, dorsal view of mesosoma.

FIGURE 31. T 2 apical impressed area, indicated by arrow (A) punctate, (B) impunctate. (From Gibbs 2010 b).