Lasioglossum (Dialictus)

Gardner, Joel & Gibbs, Jason, 2020, The ‘ red-tailed’ Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic, European Journal of Taxonomy 725, pp. 1-242: 222-230

publication ID

https://doi.org/10.5852/ejt.2020.725.1167

publication LSID

lsid:zoobank.org:pub:89FA8DDF-F4B9-417A-A5AF-B2BC9660E024

DOI

http://doi.org/10.5281/zenodo.4505681

persistent identifier

http://treatment.plazi.org/id/03F287F3-2190-FF03-8BBC-F9003021F9D9

treatment provided by

Plazi

scientific name

Lasioglossum (Dialictus)
status

 

Identification keys to the western red-tailed species of Lasioglossum (Dialictus)  

Key to females

1. Tegula enlarged, reaching or nearly reaching scutellum, with inner posterior margin straight or concave, often punctate ( Fig. 91A View Fig )........................ L. hunteri (Crawford, 1932)   and similar species 1

– Tegula ovoid, impunctate, and clearly not reaching scutellum ( Fig. 91B View Fig )........................................ 2

2. Head (except clypeus and postgena) and mesonotum entirely covered in dense, yellowish, thickly plumose hairs which (unless worn) largely obscure the surface underneath ( Fig. 92 View Fig ); face relatively long (length/width ratio ~0.84).......................................................................................................... 3

– Head and mesonotum with thick hairs sparse or absent, or if more extensive, then hairs bright white and at least center of scutum largely exposed ( Fig. 67A View Fig ); face length variable ................................ 4

3. Thick hairs short and scale-like ( Fig. 92A View Fig ); body length 4.5–5 mm (sand dunes of eastern United States and Canada)................................................................................. L. vierecki ( Crawford, 1904)  

– Thick hairs long ( Fig. 92B View Fig ); body length 5.5–6 mm (mountains of California and western Nevada   )........................................................................................................... L. cembrilacus   sp. nov.

4. Mesonotum and mesepisternum entirely covered in strong tessellate to finely reticulate microsculpture, with fine, sparse punctures (i=1–4 pd) which are often obscured by microsculpture ( Fig. 93A View Fig ) ( Mexico)........................................................................................................................... 5

– Mesonotum and/or mesepisternum usually shiny and distinctly punctate at least in part ( Fig. 93C View Fig ); if covered in strong microsculpture, then more densely punctate ( Fig. 93B View Fig ) (widespread).............. 6

5. Frons punctures large (about as large as paraocular area punctures) and coarse, approaching a rugulose condition ( Fig. 94A View Fig ); T1 anterior surface shiny ( Fig. 95A View Fig ) (widespread throughout most of Mexico)......................................................................................................... L. tessellatosum   sp. nov.

– Frons punctures small (about half the size of paraocular punctures) and fine, at most very weakly rugulose above antennae ( Fig. 94B View Fig ); T1 anterior surface weakly coriarious ( Fig. 95B View Fig ) (Yucatan Peninsula) .......................................................................................................... L. meteorum   sp. nov.

6. T1 with numerous erect hairs evenly distributed across anterior face; acarinarial fan absent ( Fig. 96A View Fig ) and/or metasomal terga with extremely narrow, abruptly downcurved rims usually with dense apicolateral fringes of long, plumose hair ( Fig. 97A View Fig ) ............................................................. 7

– T1 anterior face with erect hairs absent at least medially, usually limited to lateral margins; acarinarial fan present, although often weakly developed ( Fig. 96B View Fig ); metasomal terga with broad, flat rims with apicolateral fringes of short hair ( Fig. 97B View Fig ) .................................................................................... 13

7. Scutum shiny and moderately sparsely punctate submedially (i=1–2 pd) ( Fig. 93C View Fig ); face short (length/width ratio 0.88 or less)......................................................................................................... 8

– Scutum entirely finely and densely punctate (i ≤ 1 pd) and often dull ( Fig. 93B View Fig ); face long (length/ width ratio 0.88 or more) ................................................................................................................. 10

8. Propodeum with strong V-shaped oblique carina ( Fig. 98A View Fig ); T1 anterior face with no appressed hairs................................................................................................... L. testaceum ( Robertson, 1897)  

– Oblique carina absent ( Fig. 98B View Fig ); T1 anterior face with some appressed hairs ................................ 9

9. Metasomal terga with extremely narrow, abruptly downcurved rims usually with dense apicolateral fringes of long, plumose hair ( Fig. 97A View Fig ); frons shiny with distinctly separated punctures ( Fig. 94C View Fig ); T1 anterior face with numerous long appressed hairs forming weak acarinarial fan .......................... ............................................................................................................................ L. cactorum   sp. nov.

– Metasomal terga with broad, flat rims with sparse apicolateral fringes of short, simple hair ( Fig. 97B View Fig ); frons densely reticulate-punctate ( Fig. 94A View Fig ); T1 anterior face with sparse, short appressed hairs laterally not forming distinct fan .................................................................. L. miltolepoides   sp. nov.

10. Metasomal terga always, and scutum often mostly shiny; middle tibial spur and anterior hind tibial spur minutely serrate, appearing simple ( Fig. 99A View Fig ) (mountain species)..........................................11

– Metasomal terga and scutum entirely dull; middle tibial spur and anterior hind tibial spur finely pectinate with teeth nearly half the width of the rachis ( Fig. 99B View Fig ) (desert species)........................ 12

11. Malar space as wide or wider than scape; supraclypeal area much longer than broad; scutum with slightly sparser punctures, with numerous interspaces up to 1 puncture diameter or slightly more, and more extensively shiny on average (Utah to Colorado)........................ L. griswoldi Gibbs, 2009  

– Malar space less than width of scape; supraclypeal area only slightly longer than broad; scutum with denser punctures, with only a few interspaces up to 1 puncture diameter, and less shiny on average (sometimes completely dull) (California to British Columbia)............. L. tuolumnense Gibbs, 2009  

12. T4 tomentum limited to narrow basal band; T2–3 with basolateral tomentum covering much less than half length of segment (Baja California to Arizona)................... L. petrellum ( Cockerell, 1903)  

– T4 with sparse tomentum throughout; T2–3 with sparse basolateral tomentum covering about half length of segment laterally (New Mexico to Nuevo Leon)............................ L. droegei Gibbs, 2009  

13. Forewing with all hairs white, often difficult to see; membrane hyaline; veins (excluding subcosta) usually pale amber ( Fig. 100A View Fig ) ....................................................................................................... 14

– Forewing with distinct, dark hairs in apical half or more; membrane sometimes infuscated; veins often dark brown ( Fig. 100B View Fig ).......................................................................................................... 26

14. Punctures of frons crowded (not all punctures are round), the surface thus appearing relatively dull ( Fig. 94A View Fig ), usually distinctly smaller and denser than punctures of paraocular area; and/or T1 anterior surface coriarious ( Fig. 95 View Fig B–C)......................................................................................... 15

– Punctures of frons about the same size and density as punctures of paraocular area, with at least narrow shiny interspaces, the surface thus appearing shiny ( Fig. 94 View Fig C–D); T1 anterior surface shiny ( Fig. 95A View Fig ) ........................................................................................................................................ 18

15. Supraclypeal area mostly or entirely tessellate ( Fig. 101A View Fig ); postgena mostly dull and/or lineate ( Fig. 102A View Fig ) ...................................................................................................................................... 16

– Supraclypeal area ( Fig. 101B View Fig ) and postgena ( Fig. 102B View Fig ) mostly smooth and shiny ...................... 17

16. Scutum mostly shiny with most punctures separated by about one puncture diameter ( Fig. 75A View Fig ); discs of terga black to reddish brown with metallic blue-green reflections.... L. rufornatum   sp. nov.

– Scutum mostly tessellate with all punctures separated by much less than one puncture diameter ( Fig. 8A View Fig ); metasoma usually entirely red to orange; if dark brown, then discs of terga not metallic ............................................................................................ L. arenisaltans   sp. nov. (in part)

17. Mesepisternum rugose in dorsal half or more, with thin, sparse hair ( Fig. 36B View Fig ); T1 anterior surface shiny ( Fig. 95A View Fig ); ocelli slightly enlarged, separated by much less than 1 ocellar diameter ( Fig. 103A View Fig ) ..................................................................................... L. eophilus ( Ellis, 1914)   (in part)

– Mesepisternum with crowded punctures but not rugose, with abundant tomentum ( Fig. 11B View Fig ); T1 anterior surface at least weakly coriarious ( Fig. 95B View Fig ); ocelli normal, separated by nearly 1 ocellar diameter ( Fig. 103B View Fig )......................................................................................... L. argammon   sp. nov.

18. Forewing with two submarginal cells (rarely with three in one wing); size very small (body length ~ 3.5 mm; intertegular distance ~ 0.67 mm).......................................................... L. perditum   sp. nov.

– Forewing with three submarginal cells; size usually larger (body length ~ 4 mm or more; intertegular distance ~ 0.73 mm or more) ............................................................................................................ 19

19. Metapostnotal rugae usually not reaching posterior margin within 1 or 2 ridge widths ( Fig. 104A View Fig ); scutum often sparsely punctate on both sides of parapsidal lines (i=1–4 pd); dark spiracular spots present on T2–4 ( Fig. 105A View Fig )............................................................................................................ 20

– Metapostnotal rugae usually uniformly strong and reaching posterior margin (within 1 or 2 ridge widths) ( Fig. 104B View Fig ); scutum usually more densely punctate on either side of parapsidal lines (i ≤ 2 pd); dark spiracular spots usually present on T3–4 only ( Fig. 105B View Fig ).................................... 21

20. Face long (length/width ratio ~0.84) with tomentum much sparser than on gena, surface mostly exposed ( Fig. 52C View Fig ); mesepisternum sometimes becoming areolate dorsally........ L. lilianae   sp. nov.

– Face much broader than long (length/width ratio ~0.78) with tomentum as dense as on gena, largely obscuring surface (unless worn) ( Fig. 67C View Fig ); mesepisternum always distinctly punctate throughout................................................................................................ L. pallidellum ( Ellis, 1914)  

21. Ocellocular area with moderately sparse (i= 1–3 pd), distinct punctures ( Fig. 106A View Fig ); frons, ocellocular area, scutum, and mesepisternum entirely shiny (except small tessellate patch on scutum anteromedially) ................................................................................................................................ 22

– Ocellocular area with dense (i ≤ 1 pd), sometimes obscure punctures ( Fig. 106B View Fig ); frons, ocellocular area, scutum, and/or mesepisternum usually more extensively dull ............................................... 23

22. Scutum with all hairs thickly plumose ( Fig. 46B View Fig ); mesepisternum and hypoepimeron with punctures relatively small and fine (8–9 punctures along scrobal groove) ( Fig. 46A View Fig ) ........... L. julipile   sp. nov.

– Scutum with many hairs thin and simple ( Fig. 25A View Fig ); face, mesepisternum, and hypoepimeron with punctures relatively large and coarse (6–7 punctures along scrobal groove) ( Fig. 25B View Fig ) .................... ........................................................................................................................... L. clavicorne   sp. nov.

23. T1 and T2 with extensive lateral tomentum ( Fig. 1 View Fig ); mesepisternum usually with crowded, indistinct punctures dorsally; pronotal angle usually about 90 degrees ( Fig. 107A View Fig ) .......................................... ....................................................................................... L. hudsoniellum ( Cockerell, 1919)   (in part)

– T1 and T2 with tomentum absent or limited to thin basal band; mesepisternum usually with distinct, round punctures throughout; pronotal angle obtuse ( Fig. 107B View Fig )..................................................... 24

24. Metasoma red-orange with the following areas usually brown: basal half of T1, median transverse band on T3, and T4–5 ( Fig. 78D View Fig ); scutum punctures relatively coarse (2–3 punctures present between posterior end of parapsidal line and lateral edge of scutum) .................. L. spivakae   sp. nov. (in part)

– Metasoma entirely red-orange; scutum punctures relatively fine (3–5 punctures present between posterior end of parapsidal line and lateral edge of scutum) ........................................................... 25

25. T2–4 with tomentum absent or thin and not well differentiated from surrounding simple hairs ( Fig. 28D View Fig ); scutum hairs usually mostly thin and simple; anteromedial scutum punctures usually finer and less distinct than those elsewhere on scutum ( Fig. 28A View Fig ) ...... L. clematisellum ( Cockerell, 1904)  

– Distinct tomentum present on T2 basolaterally, T3 basally, and T4 throughout ( Fig. 22D View Fig ); scutum hairs mostly densely plumose; anteromedial scutum punctures usually as distinct as those elsewhere on scutum ( Fig. 22A View Fig ) ...................................................................................... L. clastipedion   sp. nov.

26. Mesepisternum rugulose or areolate with punctures absent or crowded and indistinct, at least in part ( Fig. 108 View Fig A–B).................................................................................................................................. 27

– Mesepisternum smooth with distinctly separated, round punctures throughout ( Fig. 108C View Fig ).......... 33

27. Supraclypeal area tessellate ( Fig. 101A View Fig ); postgena usually dull and lineate ( Fig. 102A View Fig )............... 28

– Supraclypeal area ( Fig. 101B View Fig ) and postgena ( Fig. 102B View Fig ) mostly smooth and shiny ...................... 29

28. Scutum punctures dense but mostly distinctly separated; face broad (length/width ratio ~0.82); clypeus apical margin black or brown ..................................................... L. pictum ( Crawford, 1902)  

– Scutum punctures very dense, almost all touching; face long (length/width ratio ~0.85); clypeus apical margin sometimes orange...................................................... L. arenisaltans   sp. nov. (in part)

29. Ocelli slightly enlarged (separated by less than two thirds of one ocellar diameter) ( Fig. 103A View Fig ); mesepisternum mostly rugose to rugulose with few or no distinct punctures ( Fig. 108A View Fig ) ............. 30

– Ocelli normal (separated by more than two thirds of one ocellar diameter) ( Fig. 103B View Fig ); mesepisternum usually distinctly punctate at least in ventral half ( Fig. 108B View Fig ) ........................................................ 31

30. T2–4 with extensive dense tomentum on basolateral areas of T2–3 and throughout T4 ( Fig. 36D View Fig ); clypeus apical margin black to reddish brown; legs and metasoma mostly reddish brown ................ ........................................................................................................ L. eophilus ( Ellis, 1914)   (in part)

– T2–4 with tomentum very sparse or absent ( Fig. 38D View Fig ); clypeus apical margin, legs, and metasoma often extensively orange...................................................................................... L. festinum   sp. nov.

31. Pronotal angle usually about 90 degrees ( Fig. 107A View Fig ); dark spiracular spots present on T3–4 only ( Fig. 105B View Fig ); apical impressed areas of T2–3 usually shiny and distinctly punctate; clypeus with weak, obtuse apicolateral denticles ( Fig. 3B View Fig )................ L. hudsoniellum ( Cockerell, 1919)   (in part)

– Pronotal angle obtuse ( Fig. 107B View Fig ); dark spiracular spots present on T2–4 ( Fig. 105A View Fig ); apical impressed area of T3 and sometimes T2 coriarious with punctures obscure; clypeus with strong, acute apicolateral denticles ( Fig. 3A View Fig ) .............................................................................................. 32

32. Frons punctures fine and dense but distinctly separated ( Fig. 94B View Fig ); T2–4 usually with extensive dense tomentum on basolateral areas of T2–3 and throughout T4 ( Fig. 55C View Fig ); scutum relatively long (length/width ratio usually ± 0.84) ...................................... L. mesillense ( Cockerell, 1898)   (in part)

– Frons punctures coarse and crowded ( Fig. 94A View Fig ); T2–4 with sparse tomentum limited to basal margins of T2–3 and basal half of T4 ( Fig. 64D View Fig ); scutum relatively broad (length/width ratio usually ≤ 0.8)................................................................................................................... L. minckleyi   sp. nov.

33. Hypoepimeron and upper mesepisternum densely punctate (i <1 pd); surface usually shiny........ 34

– Hypoepimeron and upper mesepisternum relatively sparsely punctate with many punctures separated by 1 puncture diameter or more, or if somewhat dense, then surface entirely imbricate................ 37

34. Dark spiracular spots present on T3–4 only ( Fig. 105B View Fig ); apical impressed areas of T2–3 usually shiny and distinctly punctate ........................................................................................................... 35

– Dark spiracular spots present on T2–4 ( Fig. 105A View Fig ); apical impressed area of T3 and sometimes T2 coriarious with punctures obscure ................................................................................................... 36

35. T2–3 with dense tomentum forming complete lateral and basal bands and apical band on T3 ( Fig. 1 View Fig ); pronotal angle about 90 degrees ( Fig. 107A View Fig ); metasoma colour pattern highly variable .......................................................................... L. hudsoniellum ( Cockerell, 1919)   (in part)

– T2–3 with tomentum absent or limited to sparse lateral patches and apical band on T3 ( Fig. 78D View Fig ); pronotal angle obtuse ( Fig. 107B View Fig ); metasoma red-orange with basal half of T1, median transverse band on T3, and T4–5 usually brown ( Fig. 78D View Fig ) ................................... L. spivakae   sp. nov. (in part)

36. Hypoepimeron and upper mesepisternum punctures usually finer, more crowded, and less distinct than lower mesepisternum punctures ( Fig. 108B View Fig ); frons punctures uniformly fine and distinctly separated ( Fig. 55D View Fig ) ............................................................ L. mesillense ( Cockerell, 1898)   (in part)

– Hypoepimeron and mesepisternum punctures uniformly large and distinctly separated ( Fig. 108C View Fig ); frons punctures larger, becoming crowded medially ( Fig. 43B View Fig ) .................. L. imbriumbrae   sp. nov.

37. Pronotal ridge sharply carinate along full height of pronotum ( Fig. 109A View Fig ); scutum and scutellum shiny and very sparsely punctate (i=1–6 pd); metapostnotum mostly shiny with rugae reaching halfway or less to posterior margin.......................................................... L. kunzei ( Cockerell, 1898)  

– Pronotal ridge absent ( Fig. 109B View Fig ); scutum and scutellum more extensively tessellate and densely punctate (i=1–4 pd); metapostnotum dull with rugae usually reaching more than halfway to posterior margin .............................................................................................................................................. 38

38. Acarinarial fan well-developed with dense appressed hairs, at least laterally ( Fig. 95C View Fig ); postgena usually dull and lineolate throughout ( Fig. 102A View Fig )........................................................................... 39

– Acarinarial fan weak, with only a few sparse appressed hairs ( Figs 95B View Fig , 96B View Fig ); postgena usually smooth and shiny in apical half or more ( Fig. 102B View Fig )...................................................................... 40

39. Head, mesosoma, and T1 anterior surface mostly shiny; metasomal terga sometimes with metallic green reflections......................................................................................... L. zephyrus ( Smith, 1853)  

– Head, mesosoma, and T1 anterior surface mostly dull; metasomal terga not metallic ....................... ............................................................................................................................. L. decorum   sp. nov.

40. T1 anterior surface coriarious ( Fig. 95C View Fig ); metasomal terga without tomentum ( Fig. 13D View Fig ); pronotal angle obtuse ( Fig. 107B View Fig )..................................................................................... L. austerum   sp. nov.

– T1 anterior surface shiny ( Fig. 95A View Fig ); T2–4 with extensive dense tomentum on basolateral areas of T2–3 and throughout T4 ( Fig. 85D View Fig ); pronotal angle about 90 degrees ( Fig. 107A View Fig ) ........................... ................................................................................................................................ L. torrens   sp. nov.

Key to males

1. Tegula enlarged, reaching or nearly reaching scutellum, with inner posterior margin straight or concave, often punctate ( Fig. 91A View Fig )........................ L. hunteri (Crawford, 1932)   and similar species 2

– Tegula ovoid, impunctate, and clearly not reaching scutellum ( Fig. 91B View Fig )........................................ 2

2. Scutum uniformly densely punctate with all punctures separated by less than 1 puncture diameter ( Fig. 110A View Fig )......................................................................................................................................... 3

– Scutum with punctures separated by 1 puncture diameter or more, at least submedially ( Fig. 110B View Fig ) ........................................................................................................................................................... 7

3. T1 anterior surface with dense appressed hair ( Fig. 111A View Fig ) (east of Rocky Mountains) ..................... ............................................................................................................... L. vierecki ( Crawford, 1904)  

– T1 anterior surface with no appressed hair (all hair erect) ( Fig. 111B View Fig ) (Rocky Mountains and westward)........................................................................................................................................... 4

4. Face short (length/width ratio ~0.8); clypeus with broad apical yellow band; hind basitarsus about 5 times as long as broad........................................................................... L. aquilae ( Cockerell, 1898)   3

– Face long (length/width ratio ~0.9 or greater); clypeus apical margin black to reddish brown; hind basitarsus less than 4 times as long as broad..................................................................................... 5

5. F2–10 about 1.5 times as long as broad; T1 entirely shiny (mountains of California to British Columbia) .............................................................................................. L. tuolumnense Gibbs, 2009  

– F2–10 nearly twice as long as broad; T1 at least faintly coriarious to reticulate (deserts of southern California to Nuevo Leon)................................................................................................................. 6

6. T1–3 coriarious to imbricate with punctures distinct throughout ( Fig. 112A View Fig ) (Baja California to Arizona) .............................................................................................. L. petrellum ( Cockerell, 1903)  

– T1–3 becoming reticulate with punctures somewhat obscure apically ( Fig. 112B View Fig ) (New Mexico to Nuevo Leon)................................................................................................... L. droegei Gibbs, 2009  

7. Clypeus metallic blue-green all the way to the apical rim, sparsely punctate (i=1–5 pd), and with tomentum sparse or absent at least in part ( Fig. 113A View Fig ) ..................................................................... 8

– Clypeus black, brown, or yellow in apical sixth or more, densely punctate (i <1 pd), and/or surface completely obscured by dense tomentum ( Fig. 113B View Fig ) .................................................................... 10

8. T1–6 with abundant tomentum and metallic blue-green at least on base of T1 ( Fig. 76D View Fig ); metasomal sterna with very long hair (2–4 OD); gonostylus very hairy and projecting laterally beyond gonocoxite ( Fig. 90M View Fig ) ....................................................................................................... L. rufornatum   sp. nov.

– T1–6 with tomentum sparse or absent and without metallic reflections ( Figs 59D View Fig , 61D View Fig ); metasomal sterna with shorter hair (1–2 OD); gonostylus with sparse hair and not reaching lateral edge of gonocoxite ( Fig. 90 View Fig H–I) .................................................................................................................... 9

9. Rims of T1–3 punctate ( Fig. 62D View Fig ); face with no tomentum; scutum usually mostly shiny and sparsely punctate ( Fig. 62A View Fig ) (i =1–4 pd) (Utah to California) ................................... L. miltolepoides   sp. nov.

– Rims of T1–3 impunctate ( Fig. 59D View Fig ); face below eye emargination with sparse tomentum; scutum usually mostly tessellate and very sparsely punctate (i= 1–6 pd) ( Fig. 59A View Fig ) (Yucatan Peninsula)..... ........................................................................................................................... L. meteorum   sp. nov.

10. Scutum between parapsidal lines entirely tessellate to finely reticulate and sparsely punctate ( Fig. 93A View Fig ) (i=1–4 pd) ( Mexico)................................................................... L. tessellatosum   sp. nov.

– Scutum between parapsidal lines shiny and/or densely punctate (i ≤ 1 pd), at least in part ( Figs 93C View Fig , 110B View Fig ) (widespread)...........................................................................................................................11

11. T1–4 convex in lateral view, with rims strongly downcurved ( Fig. 114A View Fig )........ L. cactorum   sp. nov.

– T1–4 flat in lateral view ( Fig. 114B View Fig ) ............................................................................................... 12

12. Antennae relatively long (as seen from below, length of F2 about twice length of F1, and F2–11 1.5–2 times as long as broad) ( Fig. 115A View Fig )....................................................................................... 13

– Antennae relatively short (as seen from below, length of F2 less than twice length of F1, and F2–11 1–1.5 times as long as broad) ( Fig. 115B View Fig )....................................................................................... 23

13. Clypeus apical half yellow; face short (length/width ratio ~0.81); retrorse lobe very narrow ( Fig. 90O View Fig ) ......................................................................................... L. testaceum ( Robertson, 1897)  

– Clypeus with apical yellow band absent or, if present, usually much less than half length of clypeus (if one third length of clypeus, then face long (length/width ratio ~0.89)); retrorse lobe broad ..... 14

14. S2–5 with dense plumose hair concentrated on apicolateral portions of S3 and lateral margins of S4–5; hair of S2 thinner and sparser and S4–5 bare apicomedially ( Fig. 116A View Fig )................................. ................................................................................................................... L. zephyrus ( Smith, 1853)  

– S2–5 with hairs of uniform density and plumosity throughout ( Fig. 116B View Fig ).................................... 15

15. Clypeus orange to yellow apically (if covered in tomentum, best seen in ventral view); pronotal lobe orange to yellow .............................................................................................................................. 16

– Clypeus black to brown apically (if covered in tomentum, best seen in ventral view); pronotal lobe usually black to brown..................................................................................................................... 18

16. Head ovoid, face long (length/width ratio ~0.89) ( Fig. 9C View Fig ).......................... L. arenisaltans   sp. nov.

– Head round, face short (length/width ratio ~0.84–0.86) ( Figs 39C View Fig , 56B View Fig )....................................... 17

17. Face below eye emargination with dense tomentum obscuring the surface underneath ( Fig. 56B View Fig ); rims of T2–3 with distinct punctures in median third or less ( Fig. 56D View Fig ); pronotal collar and metepisternum dark .................................................................................................... L. mesillense ( Cockerell, 1898)  

– Face below eye emargination with sparse tomentum not obscuring the surface underneath ( Fig. 39C View Fig ); rims of T2–3 distinctly punctate nearly all the way to the lateral edge ( Fig. 39D View Fig ); pronotal collar and metepisternum sometimes with orange patches .................................................. L. festinum   sp. nov.

18. Tomentum sparse or absent on clypeus and supraclypeal area; metasoma partially red or metallic green; forewing with three submarginal cells.................................................................................. 19

– Face below eye emargination entirely covered in dense tomentum; metasoma entirely black to brown; forewing sometimes with two submarginal cells ................................................................ 20

19. Propodeum dorsolateral slope rugose; frons, clypeus, and supraclypeal area with at least some tomentum; metasomal terga not metallic (sandy areas east of California).......................................... ................................................................................................... L. pictum ( Crawford, 1902)   (in part)

– Propodeum dorsolateral slope shiny and distinctly punctate; face with tomentum restricted to lower paraocular area; metasomal terga partially metallic green (especially base of T1) (mountains of California and western Nevada   ) ..................................................................... L. cembrilacus   sp. nov.

20. Head sparsely punctate (frons and paraocular area with i ± 1 pd and ocellocular area with i ± 2 pd) ( Fig. 94D View Fig ); propodeum lateral face usually smooth and tessellate; forewing almost always with two submarginal cells; size small (body length ~ 3.5 mm, intertegular distance ~ 0.65 mm).............................................................................................. L. perditum   sp. nov. (in part)

– Head more densely punctate (frons and paraocular area with i ≤ 1 pd and ocellocular area with i ≤ 1.5 pd) ( Fig. 94C View Fig ); propodeum lateral face usually mostly rugulose; forewing often with three submarginal cells; usually larger (body length ~ 4 mm or more, intertegular distance ~ 0.75 mm or more)................................................................................................................................................ 21

21. Scutum and metasomal terga usually with many thin, weakly plumose hairs; T2–3 with no basolateral tomentum ( Fig. 117A View Fig ) ................................................................. L. clematisellum ( Cockerell, 1904)  

– Scutum and metasomal terga with most hairs thick and densely plumose; T2–3 usually with some basolateral tomentum (but often sparse) ( Fig. 117B View Fig ) ...................................................................... 22

22. Postgena entirely dull and lineolate ( Fig. 102A View Fig ); posterior face of propodeum usually rugulose (Utah and northern Arizona) ..................................................................................... L. clastipedion   sp. nov.

– Postgena weakly lineate and usually shiny in part ( Fig. 102B View Fig ); posterior face of propodeum shiny and distinctly punctate (eastern Arizona, New Mexico, and Chihuahua)............................................ .................................................................................................................. L. julipile   sp. nov. (in part)

23. Metasomal terga with no tomentum; mesonotum and metasomal terga with most hairs thin and simple or weakly plumose ( Fig. 117A View Fig )............................................................................................ 24

– Metasomal terga with at least some basolateral tomentum; mesonotum and metasomal terga with most hairs densely plumose and thick ( Fig. 117B View Fig ).......................................................................... 28

24. Propodeum dorsolateral slope rugose........................................ L. pictum ( Crawford, 1902)   (in part)

– Propodeum dorsolateral slope smooth............................................................................................. 25

25. Mesepisternum and hypoepimeron densely punctate (i<1 pd) ........................................................ 26

– Mesepisternum and hypoepimeron sparsely punctate (i ± 1 pd) ..................................................... 27

26. Propodeum with weak microsculpture, appearing somewhat shiny; rims of T1–3 punctate basally ( Fig. 65D View Fig ); apical margin of clypeus and labrum usually orange ...................... L. minckleyi   sp. nov.

– Propodeum with strong dull microsculpture; rims of T1–3 almost completely impunctate ( Fig. 44D View Fig ); apical margin of clypeus and labrum reddish brown ...................... L. imbriumbrae   sp. nov. (in part)

27. Rims of T1–3 impunctate ( Fig. 32D View Fig ) (southern Mexico).................................... L. decorum   sp. nov.

– Rims of T1–3 punctate, at least basomedially ( Fig. 14D View Fig ) (Baja California peninsula)....................... ............................................................................................................................ L. austerum   sp. nov.

28. Pronotal ridge carinate ( Fig. 109A View Fig ); scutum and mesepisternum very finely, sparsely punctate (i=1–6 pd) ............................................................................................... L. kunzei ( Cockerell, 1898)  

– Pronotal ridge smoothly rounded ( Fig. 109B View Fig ); scutum and/or mesepisternum more densely punctate (i ≤ 2 pd) .......................................................................................................................................... 29

29. Rim of S5 concave ( Fig. 116C View Fig ) ................................................... L. hudsoniellum ( Cockerell, 1919)  

– Rim of S5 straight ( Fig. 116B View Fig ) ........................................................................................................ 30

30. Antennae clavate (F7–11 about 1.3 times as wide as basal antenna segments) ( Fig. 26C View Fig )................. ........................................................................................................................... L. clavicorne   sp. nov.

– Antennae normal (all segments about equally wide)....................................................................... 31

31. Rims of T1–3 opaque with punctures as dense and distinct as those on discs and covering entire surface ( Fig. 79D View Fig )................................................................................................. L. spivakae   sp. nov.

– Rims of T1–3 usually translucent, punctures finer and sparser than those on discs and/or restricted to basomedial area ............................................................................................................................... 32

32. Wings with membrane lightly infuscated, veins brown, and most hairs dark ( Fig. 100B View Fig )...................................................................................... L. imbriumbrae   sp. nov. (in part)

– Wings with membrane hyaline, veins light brown to amber contrasting with dark brown subcosta, and most hairs light ( Fig. 100A View Fig )...................................................................................................... 33

33. T1–5 with extensive tomentum; metasoma often partially or entirely orange ................................ 34

– Metasomal terga with tomentum limited to small basolateral patches on T2–4; metasoma all black................................................................................................................................................. 35

34. Face long (length/width ratio ~0.89); clypeus usually sparsely punctate (i =1–4 pd), often with a broad orange apical band ( Fig. 52C View Fig ) ..................................................................... L. lilianae   sp. nov.

– Face short (length/width ratio ~0.82); clypeus moderately densely punctate (i=1–2 pd) without orange apical band ( Fig. 68C View Fig ) ................................................................. L. pallidellum ( Ellis, 1914)  

35. Head sparsely punctate (frons and paraocular area with i ± 1 pd and ocellocular area with i ± 2 pd) ( Fig. 94D View Fig ); propodeum lateral face usually smooth and tessellate; forewing almost always with two submarginal cells; size small (body length ~ 3.5 mm, intertegular distance ~ 0.65 mm).............................................................................................. L. perditum   sp. nov. (in part)

– Head more densely punctate (frons and paraocular area with i ≤ 1 pd and ocellocular area with i ≤ 1.5 pd) ( Fig. 94C View Fig ); propodeum lateral face usually mostly rugulose; forewing often with three submarginal cells; slightly larger (body length ~ 4 mm, intertegular distance ~ 0.77 mm).................. .................................................................................................................. L. julipile   sp. nov. (in part)