Lasioglossum

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216: 13-26

publication ID

http://doi.org/ 10.5281/zenodo.1049595

publication LSID

lsid:zoobank.org:pub:B5AF6DF4-D3A7-4942-A94F-CC051D8074CF

persistent identifier

http://treatment.plazi.org/id/9A5987DB-A71A-FFAE-0A97-89D7FA4B0385

treatment provided by

Plazi

scientific name

Lasioglossum
status

 

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

1. Nest-building species; metafemur with strong scopa; labrum with apical process narrow ( Fig. 6 View FIGURE 6 A), dorsal keel present..... 2 - Socially parasitic species; metafemur with scopa weak or absent; labrum with apical process wide ( Fig. 6 View FIGURE 6 B), dorsal keel absent................................................................................................... 99

2. Metasomal terga black, brown or metallic.................................................................. 3

- Metasomal terga pale brownish yellow to dark red.......................................................... 91

3. Tegula ovoid, obscurely punctate ( Fig. 7 View FIGURE 7 B; except distinctly punctate in L. nymphaearum (Robertson))   ................ 4

- Tegula enlarged with distinct posterior angle, distinctly punctate ( Fig. 7 View FIGURE 7 A)....................................... 86

4. Procoxa with conical projection ( Fig. 8 View FIGURE 8 A) (propodeal dorsolateral slope with ventral margin defined by V- or U-shaped carina)................................................................................. L. illinoense (Robertson)  

- Procoxa without conical projection ( Fig. 8 View FIGURE 8 B) (propodeal dorsolateral slope with ventral margin variable, usually without V- or U-shaped carina).................................................................................... 5

5. T 1 declivitous surface with acarinarial fan of appressed hairs present, sometimes with wide dorsal/medial opening; T 1 declivitous surface without erect hairs basomedially ( Fig. 9 View FIGURE 9 A)...................................................... 6

- T 1 declivitous surface with acarinarial fan of appressed hairs absent; T 1 declivitous surface with erect hairs basomedially ( Fig. 9 View FIGURE 9 B).............................................................................................. 84

6. Mesosoma coarsely sculptured (mesoscutal punctures coarse, mesepisternum coarsely rugose or reticulate, etc.) and propodeal lateral and posterior surfaces separated by strong lateral carina ( Fig. 2 View FIGURE 2 A)......................................... 7

- Mesosoma without combination above (i. e. mesoscutal punctures fine or mesepisternum rugulose or punctate or propodeal lateral and posterior surfaces incompletely separated by lateral carina; Figs. 2 View FIGURE 2 C– 2 F)................................ 12

7. Hypostomal carinae widely divergent towards mandible bases ( Figs. 10 View FIGURE 10 C, 11 B); mesoscutum laterad of parapsidal line reticulate-rugose ( Fig. 4 View FIGURE 4 A).................................................................................. 8

- Hypostomal carinae parallel ( Fig. 10 View FIGURE 10 A, 11 A); mesoscutum laterad of parapsidal line punctate ( Fig. 4 View FIGURE 4 B) or coarsely rugose … 9

8. Protrochanter with anterior surface excavated; hypostomal carinae usually strongly produced, visibly protruding in lateral view................................................................................... L. bruneri (Crawford)  

- Protrochanter without anterior surface excavated; hypostomal carinae not strongly produced, not visibly protruding in lateral view........................................................................... L. reticulatum (Robertson)  

9 (7). Mesoscutum coarsely rugose laterally ( Fig. 127 View FIGURE 127 ); pronotal ridge sharply angled.................... L. hartii (Robertson)  

- Mesoscutum distinctly punctate laterally; pronotal ridge broadly rounded....................................... 10

10. Transverse propodeal carina not interrupted medially; tegula distinctly punctate; hypostomal carina produced distally, protruding in lateral view.............................................................. L. nymphaearum (Robertson)  

- Transverse propodeal carina, if present, interrupted medially; tegula obscurely punctate; hypostomal carina not produced distally.............................................................................................. 11

11. Mesoscutal punctures between parapsidal lines sparse (i= 1–3 d); head and mesosoma usually blue; wings white with pale venation............................................................................. L. albipenne (Robertson)  

- Mesoscutal punctures between parapsidal lines relatively dense (i= 1–1.5 d); head and mesosoma greenish; wings faintly dusky with amber venation................................................................ L. cressonii (Robertson)  

12 (6). Mesoscutal punctures laterad of parapsidal line dense, interspaces mostly less than 1.5 puncture diameters (i≤ 1.5 d) ( Figs. 4 View FIGURE 4 B– 4 D, 12 B)........................................................................................... 13

- Mesoscutal punctures laterad of parapsidal line sparse, interspaces mostly greater than 1.5 puncture diameters (i= 1.5–3 d) ( Figs. 4 View FIGURE 4 I, 12 A)...................................................................................... 77

13. Mesoscutal punctures between parapsidal lines sparse, interspaces greater than puncture diameter (i>d) ( Figs. 4 View FIGURE 4 A– 4 F, 4 H, 4 I, 13 B).............................................................................................. 14

- Mesoscutal punctures between parapsidal lines dense, interspaces less than puncture diameter (i<d) ( Figs. 4 View FIGURE 4 G, 13 A)..... 68

14. T 1 with distinct transverse band of appressed hairs at boundary of dorsal and declivitous surfaces, hair band separated from acarinarial fan by transverse glabrate area ( Fig. 14 View FIGURE 14. T 1 A)........................................ L. disparile (Cresson)  

- T 1 not as above, with, at most, scattered erect hairs at boundary of dorsal and declivitous surfaces ( Fig. 14 View FIGURE 14. T 1 B)........... 15

15. Supraclypeal area greatly convex; parapsidal line broad, wider than two puncture diameters ( Fig. 15 View FIGURE 15 B).................................................................................................. L. foveolatum (Robertson)  

- Supraclypeal area at most slightly convex; parapsidal line narrow, not wider than one puncture diameter ( Fig. 15 View FIGURE 15 A)....... 16

16. Head round to wide (length/width ratio <1.02); supraclypeal area usually wider than long.......................... 17

- Head elongate (length/width ratio> 1.03); supraclypeal area longer than wide.................................... 62

17. T 1 acarinarial fan incomplete, with medial opening ( Fig. 16 View FIGURE 16. T 1 B)............................................... 18

- T 1 acarinarial fan complete, without medial opening ( Fig. 16 View FIGURE 16. T 1 A).............................................. 45

18. Mesepisternal sculpture with sharp division between coarsely rugose dorsal half and imbricate-punctate ventral half ( Fig. 17 View FIGURE 17 B)................................................................................. L. dreisbachi (Mitchell)  

- Mesepisternal sculpture without sharp division between dorsal and ventral halves ( Fig. 17 View FIGURE 17 A)......................... 19

19. Protrochanter broad, width subequal to length ( Fig. 18 View FIGURE 18 B); mandible with dorsal margin strongly curved, narrowing suddenly at midlength ( Fig. 19 View FIGURE 19 B)................................................................ L. callidum (Sandhouse)  

- Protrochanter narrow, width approximately ½ length ( Fig. 18 View FIGURE 18 A); mandible without dorsal margin strongly curved, narrowing gradually over total length ( Fig. 19 View FIGURE 19 A).................................................................... 20

20. Hypostomal carinae divergent towards mandible bases ( Fig. 10 View FIGURE 10 B); (head often wider than mesosoma)................................................................................................. L. heterognathum (Mitchell)  

- Hypostomal carinae parallel ( Fig. 10 View FIGURE 10 A); (head usually narrower than mesosoma)................................. 21

21. T 3 –T 4 with uniquely thick, evenly spaced, longitudinally oriented hairs ( Fig. 20 View FIGURE 20. T 3 – T 4 A); (size small)....... L. imitatum (Smith)  

- T 3 –T 4 without thick, evenly spaced, longitudinally oriented hairs ( Fig. 20 View FIGURE 20. T 3 – T 4 B); (size variable)........................ 22

22. Mesepisternum rugulose, tessellate or weakly punctate, posterior portion relatively unsculptured, area anterior to mesocoxa never coarsely rugoso-carinulate........................................................................ 23

- Mesepisternum rugose, posterior portion distinctly sculptured, area anterior to mesocoxa usually coarsely rugoso-carinulate ( Fig. 17 View FIGURE 17 A)......................................................................................... 44

23. Clypeus with margin distal to preapical fimbriae narrow, appearing as a continuation of the lateral margins converging below the suborbital line (i. e. clypeal margin with trapezoidal appearance) ( Fig. 21 View FIGURE 21 A)................................... 24

- Clypeus with margin distal to preapical fimbriae wide, appearing divergent from the lateral margins converging below the sub- orbital line (i. e. clypeal margin with rectangular appearance) ( Fig. 21 View FIGURE 21 B)........................................ 42

24. T 2 –T 4 with tomentum at least forming distinct basolateral patches; T 3 –T 4 apical fringes present, usually dense ( Fig. 22 View FIGURE 22 B)...................................................................................................... 25

- T 2 –T 4 with very sparse, virtually absent tomentum, at most limited to scattered basolateral hairs, T 3 –T 4 apical fringes absent or very sparse ( Fig. 22 View FIGURE 22 A)............................................................................... 36

25. T 1 anterior surface dull due to presence of distinct, transversely lineolate, microsculpture.......................... 26

- T 1 anterior surface polished due to nearly complete absence of microsculpture................................... 30

26. T 1 acarinarial fan with wide dorsal/medial opening, approximately equal to width of lateral hair patches; T 3 apical margin brownish yellow with distinct apical fringe............................................................... 27

- T 1 acarinarial fan with narrow dorsal/medial opening, much less wide than lateral hair patches; T 3 apical margin dark reddish brown without distinct apical fringe..................................................................... 29

27. Gena wider than eye; clypeus distinctly flat................................................ L. apocyni (Mitchell)  

- Gena narrower than eye; clypeus slightly convex........................................................... 28

28. Mesoscutum tessellate; T 3 –T 4 with abundant tomentum and dense apical hairs forming dense apical fringes; lower paraocular area with dense punctures (i≤d)........................................... L. paradmirandum (Knerer and Atwood)  

- Mesoscutum weakly imbricate; T 3 –T 4 with moderately sparse tomentum and sparse apical hairs forming sparse apical fringes; lower paraocular area with relatively sparse punctures (i= 1–1.5 d)................................ L. fattigi (Mitchell)  

29 (26). T 2 apical impressed area impunctate; gena usually subequal to eye.................... L. laevissimum (Smith)   [in part]

- T 2 apical impressed area punctate; gena narrower than eye............................ L. gotham Gibbs   , new species

30 (25). Metapostnotal rugae not extending much more than halfway to posterior margin ( Fig. 23 View FIGURE 23 B); metasomal terga with metallic reflections; mesepisternum distinctly but minutely punctate............................. L. zephyrum (Smith)   [in part]

- Metapostnotal rugae extending more than 2 / 3 distance to posterior margin ( Fig. 23 View FIGURE 23 A); metasomal terga usually brown; mese- pisternum at most obscurely punctate.................................................................... 31

31. T 2 apical impressed area with dense and distinct punctures, not interrupted or sparser medially..................... 32

- T 2 apical impressed area with sparse or obscure punctures, interrupted or sparser medially......................... 34

32. Mesoscutum polished posteriorly due to lack of distinct microsculpture; tegula pale; clypeus not protruding much below sub- orbital line................................................................ L. trigeminum Gibbs   , new species

- Mesoscutum dull posteriorly due to presence of distinct microsculpture; tegula pale to brown; clypeus variable......... 33

33. Tegula usually dark brown; clypeus protruding ½ below suborbital line; T 2 apical impressed area with narrow testaceous bor- der.............................................................................. L. versatum (Robertson)  

- Tegula pale straw; clypeus protruding 2 / 3 below suborbital line; T 2 apical impressed area with wide testaceous border.................................................................................... L. admirandum (Sandhouse)  

34 (31). Supraclypeal area densely punctate, interspaces mostly less than puncture diameter (i≤d)........... L. sagax (Sandhouse)  

- Supraclypeal area sparsely punctate, interspaces greater than puncture diameter at least medially (i= 1–3 d).............. 35

35. Mesoscutum dull due to microsculpture; metasomal terga lacking distinct metallic reflections.......... L. ephialtum Gibbs  

- Mesoscutum polished due to microsculpture; metasomal terga with distinct metallic reflections (Sable Island, Nova Scotia)......................................................................................... L. sablense Gibbs  

36. (24). Mesoscutum mostly polished due to weakness of microsculpture.............................................. 37

- Mesoscutum dull or weakly polished due to presence of distinct microsculpture................................... 38

37. T 2 basomedially with relatively dense punctation, interspaces not greater than two puncture diameters (i<2 d), apical impressed area with scattered punctures across surface........................................... L. subviridatum (Cockerell)  

- T 2 basomedially with sparse punctation, interspaces often greater than four puncture diameters (i= 2–5 d), apical impressed area with only a few lateral punctures........................................................ L. abanci (Crawford)  

38 (36). Head relatively long (length/width ratio> 0.97); metapostnotal rugae not reaching posterior margin, sometimes medial carina usually distinctly longer than submedial rugae; metasomal terga with scattered basolateral tomentum................. 39

- Head relatively short (length/width ratio <0.95); metapostnotal rugae reaching posterior margin; metasomal terga with virtu- ally no tomentum.................................................................................... 40

39. T 2 apical impressed area impunctate; mesepisternum impunctate; metapostnotum with medial carina noticeably longer than submedial rugae....................................................................... L. planatum (Lovell)  

- T 2 apical impressed area punctate laterally; mesepisternum obscurely punctate; metapostnotum without medial carina longer than submedial rugae.............................................................. L. taylorae Gibbs   [in part]

40 (38). Mesoscutal punctures relatively dense between parapsidal lines, interspaces often less than 1.5 puncture diameters (i= 1–1.5 d); mesepisternum punctate............................................................. L. subversans (Mitchell)  

- Mesoscutal punctures relatively sparse between parapsidal lines, interspaces often equal to 2 puncture diameters (i= 1–2.5 d); mesepisternum impunctate............................................................................. 41

41. Head and mesosoma bluish; mesoscutal punctures and mesepisternal rugae relatively coarse; tegula dark reddish brown........................................................................................ L. oblongum (Lovell)  

- Head and mesosoma greenish; mesoscutal punctures and mesepisternal rugae relatively fine; tegula pale yellow............................................................................................ L. alachuense (Mitchell)  

42 (23). Mesoscutum polished due to weak microsculpture; metatibia with extensive yellowish areas not limited to ends (Southern)..................................................................................... L. leviense (Mitchell)  

- Mesoscutum dull due to microsculpture; metatibia with yellowish areas limited to ends............................. 43

43. T 1 acarinarial fan with narrow dorsal opening, clearly narrower than lateral acarinarial patches... L. mitchelli Gibbs   [in part]

- T 1 acarinarial fan with wide dorsal opening, nearly as wide as lateral acarinarial patches............. L. weemsi (Mitchell)  

44 (22). Head and mesosoma bluish; supraclypeal area sparsely punctate (i= 1–4 d); metapostnotum with rugae not reaching posterior margin; T 4 with very sparse tomentum not obscuring surface...................................... L. atwoodi Gibbs  

- Head and mesosoma greenish; supraclypeal area more densely punctate (i= 1–2 d); metapostnotum with rugae reaching or nearly reaching posterior margin; T 4 with sparse tomentum partially obscuring surface............. L. viridatum (Lovell)  

45 (17). Mesepisternum rugulose to reticulate without distinct punctures ( Fig. 24 View FIGURE 24 B)...................................... 46

- Mesepisternum smooth with distinct punctures ( Fig. 24 View FIGURE 24 A).................................................... 53

46. Clypeus with margin distal to preapical fimbriae wide, appearing divergent from the lateral margins converging below the sub- orbital line (i. e. clypeal margin with rectangular appearance) ( Fig. 21 View FIGURE 21 B)..................... L. mitchelli Gibbs   [in part]

- Clypeus with margin distal to preapical fimbriae narrow, appearing as a continuation of the lateral margins converging below the suborbital line (i. e. clypeal margin with trapezoidal appearance) ( Fig. 21 View FIGURE 21 A).................................... 47

47. Mesoscutal punctures relatively dense between parapsidal lines (i= 1–1.5 d); propodeum with oblique carina very fine, obscure or absent ( Fig. 2 View FIGURE 2 D– 2 F)................................................................................ 48

- Mesoscutal punctures relatively sparse between parapsidal lines (i= 1–2.5 d); propodeum with oblique carina fine but distinctly present ( Fig. 2 View FIGURE 2 B, 2 C).................................................................................. 51

48. Postgena lineate; mesoscutal punctures relatively coarse ( Fig. 76 View FIGURE 76 ); T 1 acarinarial fan sparse.......... L. ceanothi (Mitchell)  

- Postgena polished due to weak microsculpture; mesoscutal punctures fine; T 1 acarinarial fan dense................... 49

49. Metasomal terga relatively dull, light brown basally not contrasting sharply with pale apical margins; T 2 apical impressed area not distinctly punctate....................................................... L. katherineae Gibbs   , new species

- Metasomal terga relatively shiny, green to black basally contrasting sharply with pale apical margins; T 2 apical impressed area distinctly punctate.................................................................................... 50

50. Metapostnotal rugae longitudinal; T 1 acarinarial fan medially interrupted by subdorsal, inverted triangular, glabrous patch................................................................... L. georgeickworti Gibbs   , new species [in part]

- Metapostnotal rugae anastomosing; T 1 acarinarial fan not interrupted by glabrous area.......... L. sheffieldi Gibbs   [in part]

51 (47). Metasoma bright blue, without distinct patches of tomentum........................ L. coeruleum (Robertson)   [in part]

- Metasoma brown to black, with distinct patches of tomentum.................................................. 52

52. Propodeum with dorsolateral slope rugose ( Fig. 25 View FIGURE 25 A); mesepisternum rugose; T 3 –T 5 with hairs forming apical fringe.............................................................................................. L. timothyi Gibbs  

- Propodeum with dorsolateral slope ruguloso-imbricate ( Fig. 25 View FIGURE 25 B); mesepisternum rugulose; T 3 –T 5 without hairs forming api- cal fringe........................................................................ L. smilacinae (Robertson)  

53 (45). Tibiae and femora primarily orange-yellow............................................. L. tarponense (Mitchell)  

- Tibiae and femora primarily brown....................................................................... 54

54. Metapostnotum with rugae reaching more than 2 / 3 distance to posterior margin ( Fig. 23 View FIGURE 23 A).......................... 55

- Metapostnotum with rugae reaching ½ distance to posterior margin or less ( Fig. 23 View FIGURE 23 B).............................. 61

55. T 2 apical impressed areas with punctures absent or sparse; T 3 –T 4 with tomentum absent or limited to basolateral portions ( Fig. 22 View FIGURE 22 A).......................................................................................... 56

- T 2 apical impressed areas with punctures relatively dense; T 3 –T 4 with tomentum on majority of disc ( Fig. 22 View FIGURE 22 B)......... 60

56. Body size relatively large; metasomal terga distinctly blue or black............................................. 57

- Body size relatively small; metasomal terga light brown to golden green......................................... 58

57. Body entirely blue.......................................................... L. coeruleum (Robertson)   [in part]

- Head and mesosoma golden green, metasoma black.............................. L. nigroviride (Graenicher)   [in part]

58 (56). Submarginal cells two ( Fig. 5 View FIGURE 5 B); mesepisternal punctures contiguous........................ L. anomalum (Robertson)  

- Submarginal cells three ( Fig. 5 View FIGURE 5 A); mesepisternal punctures distinctly separated.................................... 59

59. Head and mesosoma golden green; mesoscutum with yellowish woolly hairs; metasomal terga with metallic reflections........................................................................................... L. cattellae (Ellis)  

- Head and mesosoma bluish; mesoscutum with dull whitish woolly hairs; metasomal terga without metallic reflections........................................................................................... L. tenax (Sandhouse)  

60 (55). Metapostnotal rugae longitudinal; T 1 acarinarial fan medially interrupted by subdorsal, inverted triangular, glabrous patch................................................................. L. georgeickworti Gibbs   , new species [in part]

- Metapostnotal rugae anastomosing; T 1 acarinarial fan not interrupted by glabrous area.......... L. sheffieldi Gibbs   [in part]

61 (54). Metasomal terga without metallic reflections; lower paraocular without dense tomentum; gena narrower than eye (south-eastern)........................................................................ L. flaveriae (Mitchell)   [in part]

- Metasomal terga with green metallic reflections; lower paraocular area with dense tomentum; gena usually wider than eye................................................................................ L. zephyrum (Smith)   [in part]

62 (16). Metasoma metallic, T 3 –T 4 mostly obscured by dense white tomentum....................... L. pruinosum (Robertson)  

- Metasoma non-metallic, T 3 –T 4 only partially obscured by relatively sparse tomentum.............................. 63

63. Mesoscutal punctures between parapsidal lines relatively sparse, often more than 2 punctures diameter apart ( Fig. 122 View FIGURE 122 )... 64

- Mesoscutal punctures between parapsidal lines relatively dense, only separated by 1 puncture diameter medially ( Fig. 205 View FIGURE 205 )..................................................................................................... 67

64. Metapostnotal rugae distinct on weakly imbricate background; (T 1 acarinarial fan with dorsal opening)................................................................................................. L. taylorae Gibbs   [in part]

- Metapostnotal rugae very fine, obscure on tessellate background; (T 1 acarinarial fan variable)........................ 65

65. Mesoscutal punctures immediately mesad of parapsidal line dense, interspaces not greater than puncture diameter (i≤d) ( Fig. 122 View FIGURE 122 )........................................................................... L. halophitum (Graenicher)  

- Mesoscutal punctures immediately mesad of parapsidal line sparse, interspaces greater than puncture diameter (i= 2–4 d) ( Fig. 80 View FIGURE 80 )................................................................................................ 66

66. Face relatively short (length/width ratio = 1.09–1.13) ( Fig. 79 View FIGURE 79 B); T 1 acarinarial fan dense dorsally ( Fig. 80 View FIGURE 80 )......................................................................................... L. coreopsis (Robertson)   [in part]

- Face relatively long (length/width ratio = 1.20–1.21) ( Fig. 150 View FIGURE 150 B); T 1 acarinarial fan sparse dorsally ( Fig. 151 View FIGURE 151 ) (Southern)................................................................................ L. longifrons ( Baker)   [in part]

67 (63). T 1 acarinarial fan small, dorsomedially without erect hairs ( Fig. 86 View FIGURE 86 ); T 2 apical impressed area dull, punctures obscure; mesoscutellum usually with submedial punctures widely spaced, interspaces greater than puncture diameter (i= 1–3 d).................................................................................. L. creberrimum (Smith)   [in part]

- T 1 acarinarial fan large, dorsomedially with erect hairs ( Fig. 205 View FIGURE 205 ); T 2 apical impressed area smooth, punctures distinct; mesoscutellum with submedial punctures uniformly dense, interspaces not greater than puncture diameter (i≤d)...................................................................................... L. tamiamense (Mitchell)   [in part]

68 (13). Head relatively elongate (length/width ratio = 1.00– 1.10); mesepisternum rugulose................................ 69

- Head relatively wide (length/width ratio = 0.95–0.99); mesepisternum at least obscurely punctate..................... 76

69. Metapostnotal rugae high and distinct, background microsculpture imbricate; (metasoma metallic blue or green)......... 70

- Metapostnotal rugae low and indistinct, background microsculpture granular (e.g. Fig. 205 View FIGURE 205 ); (metasoma brown, except for L. floridanum (Robertson))   ............................................................................... 72

70. Lateral margins of clypeus below suborbital line subparallel distally; pubescence yellowish............. L. pilosum (Smith)  

- Lateral margins of clypeus below suborbital line convergent distally, if nearly parallel then pubescence dull white........ 71

71. Pubescence yellowish to dull white; supraclypeal area relatively short, 0.65–0.86 times length of clypeus (eastern).......................................................................................... L. leucocomum (Lovell)  

- Pubescence dull white; supraclypeal area relatively long, 0.80–0.90 times length of clypeus (Midwestern)................................................................................................... L. succinipenne (Ellis)  

72 (69). Metasomal terga metallic green; wings relatively hyaline; pterostigma pale honey-coloured...... L. floridanum (Robertson)  

- Metasomal terga brown; wings relatively dusky; pterostigma brown............................................ 73

73. Supraclypeal area distinctly flat; T 2 apical impressed areas with deep and distinct punctures; head shorter (length/width ratio = 1.00– 1.05).......................................................................................... 74

- Supraclypeal area slightly convex; T 2 apical impressed areas with shallow and indistinct punctures; head longer (length/width ratio = 1.05–1.09)................................................................................... 75

74. Supraclypeal area polished due to lack of microsculpture ( Fig. 69 View FIGURE 69 B); clypeus with apical margin laterally reddish brown ( Fig. 69 View FIGURE 69 B).......................................................................... L. batya Gibbs   , new species

- Supraclypeal area dull due to imbricate microsculpture ( Fig. 170 View FIGURE 170 B); clypeus with apical margin entirely brown ( Fig. 170 View FIGURE 170 B).................................................................................. L. raleighense (Crawford)  

75 (73). T 1 acarinarial fan small, dorsomedially without erect hairs ( Fig. 86 View FIGURE 86 ); T 2 apical impressed area dull, punctures obscure; mesoscutellum usually with submedial punctures widely spaced, interspaces greater than puncture diameter (i= 1–3 d).................................................................................. L. creberrimum (Smith)   [in part]

- T 1 acarinarial fan large, dorsomedially with erect hairs ( Fig. 205 View FIGURE 205 ); T 2 apical impressed area smooth, punctures distinct; mesoscutellum with submedial punctures uniformly dense, interspaces not greater than puncture diameter (i≤d)...................................................................................... L. tamiamense (Mitchell)   [in part]

76 (68). T 3 usually obscured by dense tomentum; postgena polished due to lack of microsculpture; mesoscutum polished, at least submedially........................................................................... L. perpunctatum (Ellis)  

- T 3 with tomentum limited to basolateral portions; postgena dull due to lineolate microsculpture; mesoscutum imbricate throughout (south-eastern)........................................................... L. miniatulum (Mitchell)  

77 (12). Mesepisternum relatively smooth with distinct punctures..................................................... 78

- Mesepisternum rugulose without distinct punctures.......................................................... 79

78. T 3 –T 5 apical impressed areas without hairs forming apical fringes; size large, head width = 1.94–2.11 mm; propodeal carinae and sculpture coarser ( Fig. 26 View FIGURE 26 B).............................................. L. nigroviride (Graenicher)   [in part]

- T 3 –T 5 apical impressed areas with hairs forming weak apical fringes; size normal, head width = 1.44–1.58 mm; propodeal carinae and sculpture finer ( Fig. 26 View FIGURE 26 A)..................................................... L. obscurum (Robertson)  

79 (77). Frons punctures dense; size large, head width = 1.70–182 mm; oblique carina linear, transversely directed (i. e. not U- or V- shaped)............................................................................................ 80

- Frons punctures sparse; size small, head width = 1.06–1.49 mm; oblique carina angular, with both transversely and longitudi- nally directed branches (i. e. U- or V-shaped)............................................................... 83

80. Face long (length/width ratio = 1.09–1.21); mesoscutum strongly tessellate....................................... 81

- Face short (length/width ratio = 0.92–0.96); mesoscutum imbricate............................................. 82

81. Face relatively short (length/width ratio = 1.09–1.13) ( Fig. 79 View FIGURE 79 B); T 1 acarinarial fan dense dorsally ( Fig. 80 View FIGURE 80 )......................................................................................... L. coreopsis (Robertson)   [in part]

- Face relatively long (length/width ratio = 1.20–1.21) ( Fig. 150 View FIGURE 150 B); T 1 acarinarial fan sparse dorsally ( Fig. 151 View FIGURE 151 ) (Southern)................................................................................ L. longifrons ( Baker)   [in part]

82 (80). Head round (length/width ratio = 0.92–0.93), clypeus weakly protruding below suborbital line; propodeal dorsolateral slope imbricate ( Fig. 27 View FIGURE 27 A)................................................................ L. lineatulum (Crawford)  

- Head relatively long (length/width ratio = 0.95–0.96), clypeus strongly protruding below suborbital line; propodeal dorsolat- eral slope rugose ( Fig. 27 View FIGURE 27 B) (Boreal, uncommon in USA)................................... L. novascotiae (Mitchell)  

83 (79) Mesoscutum polished due to lack of microsculpture (north-eastern, rare)......................... L. achilleae (Mitchell)  

- Mesoscutum dull due to presence of microsculpture (south-eastern, common).................... L. apopkense (Mitchell)  

84 (5). Propodeal lateral and posterior surfaces completely separated by lateral carina ( Fig. 28 View FIGURE 28 B).......... L. rufulipes (Cockerell)  

- Propodeal lateral and posterior surfaces incompletely separated by lateral carina ( Fig. 28 View FIGURE 28 A).......................... 85

85. Metapostnotal rugae not extending more than 2 / 3 distance to posterior margin....................... L. versans (Lovell)  

- Metapostnotal rugae extending ¾ or more of distance to posterior margin (rare, see comments below)..................................................................................................... L. hemimelas (Cockerell)  

86 (3). Metasoma usually with distinct metallic reflections; size larger, head width> 1.7 mm (coastal sand dune specialist).......................................................................................... L. marinum (Graenicher)  

- Metasoma without distinct metallic reflections; size smaller, head width <1.5 mm ................................. 87

87. Mesepisternum shining between punctures due to weak microsculpture......................... L. ellisiae (Sandhouse)  

- Mesepisternum dull between punctures due to microsculpture................................................. 88

88. Head and mesosoma usually blue; head relatively elongate (length/width ratio = 0.95–1.10) (south-eastern)................................................................................................... L. puteulanum Gibbs  

- Head and mesosoma green with at most bluish reflections; head relatively short (length/width ratio = 0.85 –1.00).............................................................................................................. 89

89. Inner hind tibial spur pectinate with 2 branches (not including apex of rachis) (rare, Illinois)......... L. carlinvillense Gibbs  

- Inner hind tibial spur pectinate with 3 or more branches (not including apex of rachis).............................. 90

90. Paraocular area with dense tomentum obscuring surface; metapostnotal rugae anastomosing (Florida)....................................................................................................... L. lepidii (Graenicher)  

- Paraocular area with sparse tomentum not obscuring surface; metapostnotal rugae longitudinal (mid-eastern)................................................................................................ L. tegulare (Robertson)  

91 (2). Mesoscutum densely covered in yellowish tomentum, integument mostly or entirely obscured ( Fig. 29 View FIGURE 29 B).................................................................................................... L. vierecki (Crawford)  

- Mesoscutum not densely covered with tomentum, integument not obscured ( Fig. 29 View FIGURE 29 A).............................. 92

92. Mesepisternum punctate-reticulate....................................................................... 93

- Mesepisternum impunctate............................................................................. 98

93. Metapostnotum rugose, with rugae reaching or nearly reaching posterior margin................................... 94

- Metapostnotum smooth, at most with weak rugae limited to basal margin (Southern Florida)......................... 97

94. Clypeus with apical margin reddish ( Figs. 164 View FIGURE 164 B, 200 B) (South-eastern).......................................... 95

- Clypeus with apical margin dark brown ( Fig. 62 View FIGURE 62 B) (Mid-western, North-eastern).................................. 96

95. Tegula elongate with posterior angle ( Fig. 201 View FIGURE 201 )............................................. L. surianae (Mitchell)  

- Tegula ovoid without posterior angle ( Fig. 165 View FIGURE 165 ).............................................. L. nymphale (Smith)  

96 (94). Postgena polished distally due to lack of microsculpture; metasomal terga yellowish orange (Midwestern)................................................................................................... L. pictum (Crawford)  

- Postgena dull distally due to lineolate microsculpture; metasomal terga reddish orange (Coastal).................................................................................................... L. arantium Gibbs   , new species

97 (93). Dull metallic; three submarginal cells; metapostnotum with basal rugae ( Fig. 99 View FIGURE 99 ).......... L. flaveriae (Mitchell)   [in part]

- Brilliant iridescent; two submarginal cells; metapostnotum without rugae....................... L. eleutherense (Engel)  

98 (92). Propodeum with strong lateral carina reaching dorsal margin ( Fig. 28 View FIGURE 28 B) (Midwestern/Boreal)..... L. testaceum (Robertson)  

- Propodeum with weak lateral carina not reaching dorsal margin ( Fig. 28 View FIGURE 28 A) (Florida).............. L. stuartense (Mitchell)  

99 (1). Gena width greater than eye in lateral view; mandible greatly enlarged, usually extending well beyond opposing clypeal angle.................................................................................................. 100

- Gena width subequal to eye in lateral view; mandible only slightly enlarged, not extending much or at all past opposing clypeal angle............................................................................................. 107

100. Metapostnotum smooth, with weak rugae limited to basal margin.............................................. 101

- Metapostnotum rugose, with rugae reaching or nearly reaching posterior margin.................................. 102

101. Size small, head width 1.25–1.30 mm .................................................. L. lionotum (Sandhouse)  

- Size large, head width 1.80–2.02 mm .................................................. L. cephalotes (Robertson)  

102 (100). Mandible without preapical tooth ( Fig. 30 View FIGURE 30 A)........................................................... 103

- Mandible with distinct preapical tooth ( Fig. 30 View FIGURE 30 B).......................................................... 105

103. Mesepisternum distinctly punctate................................................. L. ascheri Gibbs   , new species

- Mesepisternum rugulose.............................................................................. 104

104. Mandible narrow, evenly convergent over entire length; labrum with weak basal tubercle....... L. rozeni Gibbs   , new species

- Mandible wide, strongly convergent near apex; labrum with strong basal tubercle....... L. platyparium (Robertson)   [in part]

105 (102). Mesepisternum rugulose; mandible preapical tooth very small................... L. platyparium (Dalla Torre)   [in part]

- Mesepisternum vertically carinulate or smooth and punctate; mandible preapical tooth relatively large................ 106

106. Mesepisternum vertically carinulate, impunctate........................................ L. michiganense (Mitchell)  

- Mesepisternum smooth, punctate................................................ L. curculum Gibbs   , new species

107 (99). Pronotal ridge smoothly rounded; mandible without preapical tooth........................... L. simplex (Robertson)  

- Pronotal ridge sharply angled; mandible with or without preapical tooth........................................ 108

108. Mandible with preapical tooth; inner metatibial spur usually with 3 branches.............. L. izawsum Gibbs   , new species

- Mandible without preapical tooth; inner metatibial spur with 4 branches................ L. furunculum Gibbs   , new species