Key to species of the salvini clade based on the worker caste

Two species, both described from Cuba, that are potentially members of the salvini clade were unable to be observed for this study. Therefore, Temnothorax cuyaguateje (Fontenla) and T. imias (Fontenla) are incertae sedis in Temnothorax .

1. Body without standing setae of any kind, except on the clypeus and borders of the gastral sclerites; propodeum strongly depressed; propodeal spines long and down curved; petiolar node subquadrate; southern Texas to Nicaragua ........... T. misomoschus sp. nov. ( misomoschus group)

- Body with standing setae: may be sparse, but at least present on the dorsum of the head, dorsum of the pronotum, and posterior margin of the postpetiole; other characters variable; widespread...........................................................................................................................2

2. Dorsal surfaces of legs and nearly all other surfaces of the body covered in long, tapering, suberect to subdecument setae (Figs. 37A–37C).........................................................................3

- Dorsal surfaces of legs without long, tapering, suberect setae: long suberect setae, if present, are restricted to the ventral surface of the legs (Figs. 37D–37F)...........................15

3. In profile view, promesonotum forming a bulging, even convexity; metanotal groove impressed; propodeum strongly depressed below the level of the promesonotum (Figs. 38A & 38B); ground- or litter-nesting species; U.S.A. to Nicaragua ( pergandei group).................................................................................................................................................................4

- In profile view, promesonotum grading evenly into propodeum, not bulging; metanotal groove often obscure; propodeum not strongly depressed (Figs. 38C & 38D); nesting habitat variable....................................................................................................................................5

4. Propodeal teeth present (Fig. 38A); North America, north of the Isthmus of Tehuantepec ............................................................. T. pergandei (Emery) ( pergandei group)

- Propodeal teeth absent (Fig. 38B); propodeal angles rounded and marked by a carina; Central America, south of the Isthmus of Tehuantepec ........................... T. bison sp. nov. ( pergandei group)

5. Mesosoma strongly arched in profile view (Figs. 39A & 39B)............................................6

- Mesosoma not strongly arched in profile view: flat to slightly sinuate (Figs. 39C & 39D); arboreally-nesting species in Central America from Southern Mexico to Panama ( salvini group, in part).....................................................................................................................................7

6. Dorsum of head above compound eyes and dorsum of mesosoma smooth and shining (Figs. 39A & 39E); integument predominantly dark brown to black; nesting in hollow twigs in the leaf litter, in dead branches, or under bark near the ground on live trees; Sonoran Desert.................................................. T. politus (Smith) ( subditivus group, part)

- Dorsum of head above compound eyes and dorsum of mesosoma areolate, with overlying rugose sculpture (Figs. 39B & 39F); integument predominantly yellow to testaceous; nesting habitat unknown, collected from leaf litter extractions; Southern Mexico to Honduras ( salvini group, in part)................ T. terraztecus sp. nov. ( salvini group, part)

7. Petiolar node strongly squamiform, broadly expanded apically: PNWI ≥ 160, corners distinctly angulate in posterior view (Fig. 40A)..........................................................................8

- Petiolar node not as strongly squamiform, not as broadly expanded apically: PNWI ≤

150, corners rounded in posterior view (Fig. 40B)...................................................................11

8. Light yellow to color orange, subpetiolar tooth acutely spiniform (Fig. 41A)................9

- Color dark brown, subpetiolar tooth minute and triangular (Fig. 41B).... T. longicaulis stat. nov., nom. nov. ( salvini group, part)

9. Dorsum of head with strongly rugose sculpture overlying areolate sculpture; subpetiolar tooth shorter than the setae that arises from the peduncle directly above it (Fig. 42A; may be decumbent in some specimens); dorsum of petiolar node and postpetiole lightly sculptured; size larger: WL> 1.25 mm .......... T. aztecoides sp. nov. ( salvini group, part)

- Dorsum of head with weaker, costate-rugose sculpture overlying areolate sculpture; subpetiolar tooth longer: equal to or longer than the setae that arise from the peduncle directly above it (Fig. 42B; may be decumbent in some specimens); dorsum of petiolar node and postpetiole smooth and shining to very weakly areolate-rugulose; size smaller: WL <1.17 mm .................................................................................................................................10

10. Propodeal spines longer than the propodeal declivity: PSI> 32 (Fig. 43A).................... .................................................................................. T. aztecus (Wheeler) ( salvini group, part)

- Propodeal spines shorter than the propodeal declivity: PSI <30 (Fig. 43B)....................... ................................................................................ T. paraztecus sp. nov. ( salvini group, part)

11. Subpetiolar tooth equal to or longer than the setae that arises from the peduncle directly above it (Fig. 44A; may be decumbent in some specimens) ................. T. longinoi sp. nov. ( salvini group, part)

- Subpetiolar tooth shorter than the setae that arises from the peduncle directly above it (Fig. 44B; may be decumbent in some specimens)...................................................................12

12. Propodeal spines long: PSI> 30 (Fig. 45A)... T. quetzal sp. nov. ( salvini group, part)

- Propodeal spines shorter: PSI <30 (Fig. 45B)........................................................................13

13. Petiolar node not expanded apically: PNWI ≤ 130 (Fig. 46A)......... T. salvini (Forel) ( salvini group, part)

- Petiolar node expanded apically: PNWI ≥ 160 (Fig. 46B)...................................................14

14. Dorsum of mesosoma predominantly rugose; integument areolate between propodeal spines (Fig. 47A) ........................................ T. parvidentatus sp. nov. ( salvini group, part)

- Dorsum of mesosoma predominantly costate; integument smooth and shining between propodeal spines (Fig. 47B) ....... T. fortispinosus sp. nov. ( salvini group, part)

15. Antennal scapes with suberect pilosity (Fig. 48A); postpetiole moderately broad, 2.1 to 2.2 times the width of the caudal cylinder of the petiole in dorsal view (PSI 210-220); anterior quarter of first gastral tergite very weakly areolate; integument light yellow; Baja California .............................. T. pilicornis sp. nov. ( pilicornis group)

- Antennal scapes with subdecumbent to adpressed pilosity (Fig. 48B); postpetiole narrow to very broad; if first gastral tergite sculptured and integument yellow, then petiole narrower: less than 2 times the width of the caudal cylinder in dorsal view (PSI <200); widespread16

16. Petiolar node cuneiform to subcuneiform (Figs. 49A–49C)............................................17

- Petiolar node shaped otherwise (Figs. 49D–49F)...................................................................18

17. Anterior clypeal margin emarginate; hind femora moderately to strongly incrassate (Figs. 50A & 50B); Southern U.S.A. and Northern Mexico ( rugosus group, in part) .......... ................................................................................. T. rugosus (Mackay) ( rugosus group, part)

- Anterior clypeal margin entire; hind femora weakly incrassate (Figs. 50C & 50D); Southern Mexico (Chiapas)................ T. acuminatus sp. nov. ( acuminatus group, part)

18. Petiole with a transverse carina anterodorsally (Figs. 51A & 51B); postpetiole narrow, <1.5 times as wide as the caudal cylinder of the petiole in dorsal view (PWI <150) (Figs. 51C & 51D); Mexico .............................................................................................................19

- Petiole with a transverse carina dorsally or not (Fig. 51E); postpetiole relatively broad, ≥ 1.5 times as wide as the caudal cylinder of the petiole in dorsal view (PWI ≥ 150) (Figs. 51F–51H); widespread..........................................................................................................20

19. Anterior margin of clypeus entire (Fig. 52A); propodeum without many setae dorsally, except near extreme anterior near the metanotal groove and midway along the length of the propodeal spines (Fig. 52B); petiolar node dorsally rounded in profile view; first gastral sternite areolate-rugulose; Mexico (Veracruz) T. tuxtlanus sp. nov. ( acuminatus group, part)

- Anterior margin of clypeus emarginate (Fig. 52C); propodeum with at least one pair of setae dorsally (Fig. 52D); petiolar node dorsally truncate in profile view; first gastral sternite smooth; Mexico (Chihuahua; rugosus group, in part) ...... T. parralensis sp. nov. ( rugosus group, part)

20. With the following characters in combination: anterior margin of the clypeus strongly emarginate medially; petiolar peduncle short to moderately long, comprising half the length of the petiole or less; petiolar node subquadrate, erect, and relatively short: NI <170 (Fig. 53); arboreally-nesting species from Southwestern U.S.A. to South Central Mexico ( annexus group) .............................................................................................................................. 21

- Not having the above combination of characters; if clypeus is strongly emarginate, then petiolar peduncle is longer and/or petiolar node is not subquadrate; widespread............25

21. Erect setae present on gula (Fig. 54A)..................................................................................22

- Setae, if present on gula, not erect (Fig. 54B).........................................................................24

22. Head elongate: CI 80-84 (Fig. 55A) .............. T. balnearius sp. nov. ( annexus group)

- Head less elongate: CI 86-90 (Figs. 55B & 55C)....................................................................23

23. Petiolar node lower, not as strongly quadrate in profile view; posterior margin of petiolar node indistinct in profile view, much shorter than dorsal margin (Fig. 56A); first gastral tergite densely areolate ............................. T. obtusigaster sp. nov. ( annexus group)

- Petiolar node high and strongly quadrate in profile view; posterior margin of petiolar node distinct in profile view, about two thirds as long as dorsal margin (Fig. 56B); first gastral tergite smooth and shining ........................... T. arbustus sp. nov. ( annexus group)

24. Propodeal spines longer, broad; petiole pedunculate (Fig. 57A); body heavily sculptured: pronotum in profile view areolate with overlying rugose sculpture .................. ............................................................................. T. annexus (Baroni Urbani) ( annexus group)

- Propodeal spines shorter, less broad; peduncle of petiole shorter (Fig. 57B); body less heavily sculptured: pronotum in profile view predominantly areolate, without overlying rugose sculpture ........................................................ T. quercicola sp. nov. ( annexus group)

25. Propodeal spines long (PSI ≥ 22), acute, and directed dorsally: forming an angle of 130 ° or greater with the propodeal declivity in profile view (Fig. 58a–58C)...............................26

- Propodeal spines, if directed dorsally, not long (PSI ≤ 20; Fig. 58D–58F).................... 28

26. Dorsum of head weakly sculptured: smooth and shining between weak costulate sculpture; petiolar node erect and subquadrate (Figs. 59A & 59D); Southern Mexico ....... ........................................................ T. tenuisculptus (Baroni Urbani) ( tenuisculptus group)

- Dorsum of head strongly sculptured: uniformly areolate-rugulose with overlying costulate or rugulose sculpture; petiolar node rounded dorsally (Figs. 59B, 59C, 59E, 59F); Southern Mexico to Honduras ......................................................................................................27

27. Postpetiole relatively narrow: <1.7 times as wide as the caudal cylinder of the petiole in dorsal view (PWI <170; Fig. 60A); Southern Mexico to Honduras ....... T. acutispinosus sp. nov. ( acutispinosus group)

- Postpetiole relatively broad: about 2 times as wide as the caudal cylinder of the petiole in dorsal view (PWI ~ 200; Fig. 60B); Honduras .... T. altinodus sp. nov. ( altinodus group)

28. With the following characters in combination: dorsal surface of head uniformly areolate (Fig. 61A); petiolar peduncle moderately long, comprising less than half the petiolar length; petiolar node antero-posteriorly compressed and tall, with posterior face about as long as the anterior face in profile view (Fig. 61B); Texas and Northern Mexico ..................................................................... T. terrigena (Wheeler) ( terrigena group)

- Not matching the above description; if dorsal surface of head is uniformly areolate and petiolar peduncle is moderately long, then the petiolar node is not antero-posteriorly compressed and tall; widespread...................................................................................................29

29. Petiolar node tall and leaning posteriorly in profile view, overhanging the caudal cylinder of the petiole (Figs. 62A–62C); Mexico to Nicaragua ( augusti group)................30

- Petiolar node, if tall, not leaning posteriorly in profile view (Figs. 62D–62F); widespread..........................................................................................................................................33

30. Propodeal spines short: PSI <35 (Fig. 63A) T. augusti (Baroni Urbani) ( augusti group)

- Propodeal spines longer: PSI> 35 (Fig. 63B)........................................................................31

31. Head relatively broad: CI ≥ 84 (Fig. 64A). T. leucacanthoides sp. nov. ( augusti group)

- Head relatively narrow: CI ≤ 81 (Fig. 64B).............................................................................32

32. Antennal scapes longer: SI> 100........................... T. aureus sp. nov. ( augusti group)

- Antennal scapes shorter: SI ≤ 100. T. leucacanthus (Baroni Urbani) ( augusti group)

33. Antennal scapes long, exceeding the posterior margin of the head by about two times the maximum width of the scape when fully retracted (SI> 110); dorsum of mesosoma not strongly arched dorsally in profile view; propodeal spines shorter than the propodeal declivity (PSI <35); petiolar node subquadrate; Mexico (Puebla)........................ .................................................................................... T. casanovai sp. nov. ( casanovai group)

- Not matching the above description; if antennal scapes are long, mesosoma strongly arched dorsally, propodeal spines longer than the propodeal declivity, and petiolar node is squamiform; widespread.................................................................................................................34

34. With the following character combination: propodeal spines short (PSI <30); in profile view, dorsum of petiolar node subquadrate to rounded, and bearing four to six erect setae (Figs. 65A–65C); in dorsal view, postpetiole moderately broad (190 <PWI <235; Figs. 65D–65F); Southern Mexico to Guatemala ( goniops group, in part)................................. 35

- Not matching the above description; widespread ................................................................ 37

35. Dorsum of head and post-petiole predominantly smooth and shining (Figs. 66A &

66B)............................................................................. T. xincai sp. nov. ( goniops group, part)

- Dorsum of head and post-petiole areolate-rugulose (Figs. 66C & 66D)..........................36

36. Petiolar node expanded apically: PNWI> 120 (Fig. 67A)... T. ixili (Baroni Urbani) ( goniops group, part)

- Petiolar node not expanded apically: PNWI <115 (Fig. 67B).............. T. achii sp. nov. ( goniops group, part)

37. Petiolar node squamiform (Figs. 68A–68D).......................................................................38

- Petiolar node not squamiform (Figs. 68E–68H)....................................................................42

38. In dorsal view, propodeal spines straight and evenly diverging: negative space between the propodeal spines “V” shaped, or a basally truncate “V” (Figs. 69A–69C); dorsum of petiolar node flat, sides evenly converging basally (Figs. 69A & 69C); widespread ............. ...................................................................... T. subditivus (Wheeler) ( subditivus group, part)

- In dorsal view, propodeal spines diverging, but curved toward the midline of the body: negative space between the propodeal spines “U” shaped, or a basally truncate “U” (Figs. 69D–69F); dorsum of petiolar node rounded to flat, sides bowed (Figs. 69D–69F); Bahamas and Cuba ( pastinifer group, in part)..........................................................................39

39. Head predominantly smooth and shining (Fig. 70A) T. schwarzi (Mann) ( pastinifer group, part)

- Head sculptured: areolate to areolate-rugulose with overlying rugulose sculpture (Figs. 70B–70F)................................................................................................................................40

40. Anterior margin of clypeus strongly emarginated (Fig. 71A); in profile view, petiole strongly squamiform and overhanging the petiolar peduncle; petiole with only two erect setae dorsally, postpetiole with six or fewer (Fig. 71B) .......... T. pastinifer (Emery) ( pastinifer group, part)

- Anterior margin of clypeus entire or, if weakly indented, head and mesosoma with well-defined rugae in addition to areolae (Fig. 71C); in profile view, petiole strongly squamiform or not; petiole with four or more erect setae, postpetiole with ten or more (Fig. 71D)............................................................................................................................................41

41. Antennal scape long, surpassing posterior margin of head by> 2x the maximum width of the scape when fully retracted (SI ~ 106; Fig. 72A); petiolar node strongly enlarged apically (PNWI> 180; Fig. 72B)............ T. rutabulafer sp. nov. ( pastinifer group, part)

- Antennal scape short, barely surpassing the posterior margin of head when fully retracted (Fig. 72C); petiolar node weakly enlarged apically (PNWI <160; Fig. 72D) ....... ................................................................... T. androsanus (Wheeler) ( pastinifer group, part)

42. With the following character combination: antennal scapes surpassing the posterior margin of the head capsule by about one and a half times their length; dorsum of mesosoma strongly arched; petiole with a moderately long peduncle; petiolar node high, strongly rounded dorsally, and wider than the caudal cylinder of the petiole in dorsal view; postpetiole wide (215 <PWI <240); bicolored species: head capsule dark, remainder of body light yellow; Cuba ( pastinifer group, in part) .... T. nigricans (Baroni Urbani) ( pastinifer group, part)

- Not matching the above description; widespread..................................................................43

43. Postpetiole moderately broad (150 <PWI <220; Figs. 73A–73D); Mexico to Costa Rica .......................................................................................................................................................58

- Postpetiole very broad (PWI> 220; Figs. 73E–73H); Southern Florida, Bahamas, Greater Antilles, Northern Lesser Antilles ( pulchellus group)..............................................................44

44. Hind femora strongly incrassate (FI> 370); propodeal spines short (PSI <21) and petiole with> 4 erect setae (Fig. 74A); Hispaniola ............... T. laticrus sp. nov. ( pulchellus group)

- Hind femora not as strongly incrassate (FI <360); propodeal spines longer (PSI ≥ 30) and petiole with ≤ 4 erect setae (Fig. 74B); widespread, including Hispaniola..........................45

45. Erect setae on dorsum of mesosoma very sparse, restricted to a pair arising from the promesonotum (Figs. 75A & 75B).............................................................................................. 46

- Standing setae on dorsum of mesosoma more abundant, with erect setae on other regions of the mesosoma, in addition to the promesonotum (Figs. 75C & 75D)............................47

46. Dorsum of head and mesosoma smooth and shining; dorsum of petiole with two erect setae; bicolored: head and gaster dark brown, remainder of body yellow; U.S. and British Virgin Islands ........................................... T. pulchellus (Emery) ( pulchellus group)

- Dorsum of head and mesosoma areolate; dorsum of petiole without erect setae; uniformly testaceous yellow; Barbuda .................................... T. wettereri sp. nov. ( pulchellus group)

47. Petiole with only 2 erect setae (Figs. 76A –76C)...............................................................48

- Petiole with 4 erect setae (Figs. 76D–76F)...............................................................................50

48. Head predominantly smooth and shining, with weak costulate sculpture along the medial edges of the frontal carinae (Fig. 77A); Cuba ..............................................................49

- Head with stronger sculpture, either with a smooth central strip surrounded by weakly areolate and costulate sculpture, or with the head uniformly areolate (Figs. 77B & 77C); southern Florida, Bahamas, and Cuba ....................... T. torrei (Aguayo) ( pulchellus group)

49. In full-face view, posterior margin of head passing into the lateral margins through a broad curve, giving the head an ovular shape (Fig. 78A); in dorsal view, promesonotal suture deeply impressed and extending to the dorsal face of the mesosoma (Fig. 78B); in profile view, petiolar node subquadrate: dorsal face transitioning to posterior face through a rounded ~90 ° angle (Fig. 76C)....................... T. hippolytus sp. nov. ( pulchellus group)

- In full-face view, posterior margin of head passing into the lateral margins through a rounded angle, giving the head a boxy shape (Fig. 78C); in dorsal view, promesonotal suture not deeply impressed (Fig. 78D); in profile view, petiolar node not subquadrate: dorsal face transitioning to posterior face through broad curve (Fig. 76B).... T. terricola (Mann) ( pulchellus group)

50. Dorsum of head uniformly areolate (Figs. 79A–79C).......................................................51

- Dorsum of head smooth and shining, or sculptured otherwise (Figs. 79D –79F)........52

51. In full-face view, head with posterior margin weakly concave (Figs. 79A & 79C)........ ..................................................................................... T. agavicola sp. nov. ( pulchellus group)

- In full-face view, head with posterior margin flat to convex (Fig. 79B).... T. albispinus (Wheeler) ( pulchellus group)

52. Metapleural gland bulla large, extending more than halfway between the metacoxal insertion and the propodeal spiracle (Fig. 80A); U.S. Virgin Islands ........ T. magnabulla sp. nov. ( pulchellus group)

- Metapleural gland bulla smaller, extending about halfway between the metacoxal insertion and the propodeal spiracle (Figs. 80B–80D); Hispaniola......................................53

53. Mesosoma smooth and shining dorsally (Figs. 81A & 81D); dorsum of mesosoma strongly convex in profile view (Figs. 81B & 81C)................................................................. 54

- Mesosoma areolate-rugulose dorsally (Figs. 81E & 81H); dorsum of mesosoma weakly convex in profile view (Figs. 81F & 81G) ................................................................................. 56

54. Uniformly yellow ....................... T. flavidulus (Wheeler & Mann) ( pulchellus group)

- Color variable, but never uniformly yellow.............................................................................55

55. On anterior margin of clypeus, medial two pairs of setae about the same width (Fig. 82A); strikingly bicolored: head, mesosoma and waist segments dark brown; remainder bright yellow ..................................... T. harlequina sp. nov. ( pulchellus group)

- On anterior margin of clypeus, pair of setae flanking the medial pair about twice the width of the medial pair (Fig. 82B); integument color variable, but if bicolored, gaster never uniformly bright yellow........................ T. ciferrii (Menozzi & Russo) ( pulchellus group)

56. Anterior clypeal margin emarginated medially (Fig. 83A) ............ T. wilsoni sp. nov. ( pulchellus group)

- Anterior clypeal margin flat to evenly convex (Fig. 83B)....................................................57

57. Petiole long relative to the postpetiole (PLI 148–166; Fig. 84A).............. T. balaclava sp. nov. ( pulchellus group)

- Petiole short relative to the postpetiole (PLI 140–143; Fig. 84B)........... T. bahoruco sp. nov. ( pulchellus group)

58. Petiolar node low, elongate (NI> 170; Figs. 85A & 85B); Mexico to Costa Rica ( fuscatus group)..................................................................................................................................................59

- Petiolar node high, relatively short (NI <150; Fig. 85C & 85D); Southern Mexico and Guatemala ( goniops group, in part)..............................................................................................62

59. Propodeal spines long: PSI> 22 (Figs. 86A & 86B); body uniformly colored.......... 60

- Propodeal spines short: PSI <19 (Fig. 86C); bicolored: either with mesosoma red and rest of body dark brown, or with gaster yellow and body dark brown.......................................61

60. Propodeal spines acute (Fig. 86A) ....................... T. fuscatus (Mann) ( fuscatus group)

- Propodeal spines truncate (Fig. 86B) .................. T. nebliselva sp. nov. ( fuscatus group)

61. Eye small and round: in profile view, distance between the compound eye and base of mandible greater than the maximum length of the eye, OI ≤ 22 (Fig. 87A); body predominantly dark brown, contrasting with a red mesosoma......... T. ocarinae (Baroni Urbani) ( fuscatus group)

- Eye larger and oval: in profile view, distance between the compound eye and base of mandible roughly equal to the maximum length of the eye, OI ≥ 24 (Fig. 87B); body predominantly dark brown, with a contrasting bright yellow gaster T. skwarrae (Wheeler) ( fuscatus group)

62. Head sculptured: dorsum uniformly areolate-rugose (Fig. 88A).. T. goniops (Baroni Urbani) ( goniops group, part)

- Dorsum of head predominantly smooth and shining (Fig. 88B)..... T. huehuetenangoi (Baroni Urbani) ( goniops group, part)