Lasioglossum, Curtis, 1833

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 16-24

Key to female metallic Lasioglossum of Canada

1. Nest-building species; hind femoral scopa strong; labrum with narrow apical process and distinct dorsal keel ( Fig. 3A ); subapical tooth present ( Fig. 4A ); gena variable, usually narrower than eye, never more than 1.5 times as wide as eye ( Fig. 5A ); dorsolateral angle of pronotum usually obtuse ( Fig. 6A ) (except in L. packeri new species) ....................................................................................................................................................................... 2

- Socially parasitic species; hind femoral scopa reduced; labrum with broad apical process and no dorsal keel ( Fig. 3B ); subapical tooth often greatly reduced or absent ( Fig. 4B ); gena sometimes very wide, as much as 2 times as wide as eye ( Fig. 5B ); dorsolateral angle of pronotum orthogonal or acute ( Fig. 6B ) ......................... 94

2. Metasomal terga reddish brown to blackish or with metallic reflections ............................................................. 3

- Metasomal terga reddish orange or pale brownish yellow ................................................................................ 91

3. Three submarginal cells (vein 1rs-m present) on forewing ( Fig. 2A ) .................................................................. 4

- Two submarginal cells (vein 1rs-m absent) on forewing ( Fig. 2B ) ..................................................................... 90 4. Tegula ovoid with at most a weak posterior angle, obscurely punctate (except in L. oceanicum (Cockerell) ; Fig. 7B ) ......................................................................................................................................................................... 5

- Tegula greatly enlarged with strong posterior angle, strongly punctate ( Fig. 7A ) ............................................ 88

5. Mesoscutal punctation dense laterad of parapsidal lines (i≤d) and on anterolateral portions ( Fig. 8A ) .............. 6

- Mesoscutal punctation sparse laterad of parapsidal lines (i>1.5d) and on anterolateral portions ( Fig. 9B ) … 83

6. Lateral and posterior surfaces of the propodeum only separated on the ventral two thirds or less by a carina that does not reach the dorsolateral slope which may or may not be delimited by a weak, oblique carina ( Fig. 9A ). 7

- Lateral and posterior surfaces of the propodeum separated by carina that reaches, or nearly reaches, the dorsolateral slope which is delimited below by a strong, oblique carina ( Fig. 8B ) ..................................................... 74

7. Mesoscutal punctation between parapsidal lines moderately sparse, interspaces typically more than one puncture diameter ( Fig. 10B ) ....................................................................................................................................... 8

- Mesoscutal punctation between parapsidal lines dense, interspaces between parapsidal lines mostly or entirely less than one puncture diameter ( Fig. 10A ) ....................................................................................................... 63

8. Supraclypeal area weakly convex; parapsidal lines narrow ( Fig. 11A ) ............................................................... 9

- Supraclypeal area very strongly convex ( Fig. 111D ); parapsidal lines very wide, greater than two puncture diameters ( Fig. 11B ) ..................................................................................................... L. foveolatum (Robertson)

9. Mesepisternum without punctures ( Fig. 12B ), if any obscure punctures are present then the metasomal terga without metallic reflections ................................................................................................................................ 10

- Mesepisternum with distinct punctures at 40X magnification ( Fig. 12A ), if punctures somewhat obscure then the metasomal terga with strong metallic reflections .......................................................................................... 38

10. Metapostnotum with variable sculpture usually reaching more than halfway to posterior margin; T1 acarinarial fan present ( Fig. 13A ), sometimes weak and limited to lateral areas, but then without erect woolly hairs on centre of T1 declivitous surface ............................................................................................................................... 11

- Metapostnotum with weak striae reaching approximately halfway to posterior margin ( Fig. 14A–B ); T1 acarinarial fan absent ( Fig. 13B ), but with erect woolly hairs on centre of T1 declivitous surface .......................... 37

11. Gena narrower or equal in width to eye in lateral view ( Fig. 5A ) ..................................................................... 12

- Gena wider than eye in lateral view ( Fig. 15A–B ) ............................................................................................. 35

12. Protrochanters narrow, much longer than wide ( Fig. 16A ); dorsal margin of mandible not strongly curved at midlength ( Fig. 17A ) ........................................................................................................................................... 13

- Protrochanters very wide, nearly as wide as long ( Fig. 16B ); dorsal margin of mandible strongly curved at midlength ( Fig. 17B ) ............................................................................................................. L. callidum (Sandhouse)

13. Mesepisternum without a sharp delineation of sculpture ( Fig. 18A ) ................................................................ 14

- Mesepisternum with a sharp delineation between coarsely rugose dorsal half and punctate-imbricate ventral half ( Fig. 18B ) .......................................................................................................................... L. dreisbachi (Mitchell)

14. T1 acarinarial fan incomplete with dorsal opening ( Fig. 19B ) ........................................................................... 15

- T1 acarinarial fan complete without dorsal opening ( Fig. 19A )......................................................................... 31

15. Mesepisternum rugulose to tessellate ( Fig. 20A, 20B ) ...................................................................................... 16

- Mesepisternum strongly rugose ( Fig. 18A ) ........................................................................................................ 30

16. Distal margin of clypeus 1.1–1.2 times wider than clypeal length, lateral margins appearing distinctly convergent; apicolateral corner of clypeus rounded ( Fig. 106C ) .................................................................................. 17

- Distal margin of clypeus 1.4–1.5 times wider than clypeal length, lateral margins appearing weakly convergent; apicolateral corner of clypeus acute ( Fig. 238C ) ................................................................... L. weemsi (Mitchell)

17. T2 apical impressed area with obscure or irregularly distributed punctures, punctures absent medially ( Fig. 21B ) ............................................................................................................................................................................. 18

- T2 apical impressed area with relatively distinct and regularly distributed punctures, but often minute, punctures present medially ( Fig. 21A ) ................................................................................................................................ 27

18. Metasomal terga with very sparse, virtually absent tomentum, at most limited to scattered basolateral hairs, T3– T4 apical fringes absent or very weak ( Fig. 22A )................................................................................................ 19

- Metasomal terga with moderately abundant tomentum, at least forming distinct basolateral patches, T3–T4 apical fringes present, usually strong ( Fig. 22B ) ..................................................................................................... 23

Figures

FIGURE 2. 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.

FIGURE 3. Labrum of female Dialictus; (A) nest-building species, (B) parasitic species. Arrows indicate apical process.

FIGURE 4. Mandible of female Dialictus with subapical tooth (A) present, (B) absent, as indicated by arrow.

FIGURE 5. Gena of female Dialictus (A) narrower than eye, (B) wider than eye.

FIGURE 6. Dorsolateral angle of pronotum (A) obtuse, (B) acute.

FIGURE 7. Tegula of (A) L. imbrex (tegulare species group), (B) L. oceanicum.

FIGURE 8. Mesoscutal punctation on lateral portion of disc (A) L. obscurum, (B) L. incompletum.

FIGURE 9. Propodeum of (A) L. hudsoniellum, (B) L. testaceum.

FIGURE 10. Mesoscutal punctation (A) completely dense, (B) sparse medially (indicated by arrow).

FIGURE 11. Parapsidal line of mesoscutum, indicated by arrow, (A) narrow, (B) wide (L. foveolatum)

FIGURE 12. Mesepisternum of female (A) L. nigroviride, (B) L. oblongum.

FIGURE 13. Declivitous surface of T1 with acarinarial fan (A) present, (B) absent.

FIGURE 14. Metapostnotum of female (A) L. versans, (B) L. ruidosense.

FIGURE 15. Gena of female (A) L. zephyrum, (B) L. packeri.

FIGURE 16. Protrochanter of (A) typical Dialictus, (B) female L. callidum.

FIGURE 17. Mandible of female (A) L. coeruleum, (B) L. callidum.

FIGURE 18. Mesepisternum of female (A) L. atwoodi, (B) L. dreisbachi, arrow indicates sharply delineated change in sculpture.

FIGURE 19. T1 acarinarial fan (A) complete, without dorsal opening, (B) incomplete, with dorsal opening.

FIGURE 20. Mesepisternum (A) tessellate-imbricate (B) rugose-rugulose.

FIGURE 21. T2 apical impressed area with punctures on medial portion, indicated by arrow, (A) present, (B) absent.

FIGURE 22. T3 and T4 with tomentum (A) absent, (B) present, arrows indicate apical fringes.

FIGURE 106. Lasioglossum ephialtum new species. Female (A) lateral habitus; (B) dorsal habitus; (C) face; (D) T1, T2. Scale bars, A–C = 1 mm.

FIGURE 111. Lasioglossum foveolatum (Robertson). Female (A) lateral habitus; (B) dorsal habitus; (C) face; (D) lateral view of head; (E) mesoscutum, tegula. Scale bars, A–C = 1 mm.

FIGURE 238. Lasioglossum weemsi (Mitchell). Female (A) lateral habitus; (B) dorsal habitus; (C) face. Scale bars, A– C = 1 mm.