Nylanderia, Kallal & Lapolla, 2012

Kallal, Robert J. & Lapolla, John S., 2012, Monograph of Nylanderia (Hymenoptera: Formicidae) of the World, Part II: Nylanderia in the Nearctic 3508, Zootaxa 3508, pp. 1-64 : 7-8

Key to Nearctic Nylanderia Workers

1. Mesonotum with pubescence (figs. 7, 10, 22, 43)............................................................. 2

- Mesonotum without pubescence (figs. 13, 25, 52)............................................................ 6

2. Mesopleuron entirely covered with pubescence (figs. 7, 22).................................................... 3

- Mesopleuron not entirely covered with pubescence........................................................... 4

3. Overall color reddish-brown; typically REL less than 30; mesosoma macrosetae long (index of longest pronotal macrosetae/ propodeum height at least 60).............................................................. .. fulva or pubens *

- Overall color dark brown to almost black; typically REL more than 30; mesosoma macrosetae short (index of longest pronotal macrosetae/propodeum height less than 60)........................................................ bourbonica

4. Overall body yellow in color.................................................................. guatemalensis

- Overall body brown in color............................................................................. 5

5. Gastral macrosetae densely distributed (figs. 10, 12); HW ≥ 0.59 mm; gastral pubescence densest along segmental margins................................................................................................. bruesii

- Gastral macrosetae sparsely distributed (fig. 43, 45); HW <0.59 mm; gastral pubescence equally distributed...... steinheili

6. Whitish to pale yellow in color; macrosetae white (fig. 37)............................................. phantasma

- Darker in color than above; if yellow, then macrosetae are brown to black (fig. 40).................................. 7

7. Head ovate with distinct medial emargination along posterior margin (fig. 29), and SMC at least 10, and body overall densely setose, with black macrosetae contrasting strongly with yellow cuticle....................................... hystrix

- Not matching the combination of characters listed above...................................................... 8

8. Cuticle usually with bluish reflections under microscopic examination; pronotum with distinct concavity, giving it an angular appearance in lateral view (fig. 4)............................................................... austroccidua

- Cuticle rarely with bluish reflections under microscopic examination; pronotum not angular in appearance in lateral view... 9

9. Antennae, mesosoma and legs yellowish, and SMC 5 or more, and 3 ocelli apparent; 1 st gastral tergite often yellowish and contrasting with remainder of gaster..................................................................... flavipes

- Overall coloration variable; SMC variable; ocelli may or may not be apparent; 1 st gastral tergite always same color as remain- der of gaster......................................................................................... 10

10. Brown in color, with mesocoxae and metacoxae whitish (figs. 16, 55), contrasting strongly with mesosoma; cephalic pubescence moderate to dense (figs. 17, 56).................................................................... 11

- Yellow to brown in color, typically with mesocoxae and metacoxae the same color as mesosoma; if mesocoxae and metacoxae whitish and contrasting strongly with mesosoma then cephalic pubescence sparse to absent (figs. 50, 53)............... 12

11. Scape macrosetae count 5 or more; head length typically> 0.59 mm (HL: 0.59–0.74); usually uniform brown or with darker gaster (fig. 16)................................................................................ faisonensis

- Scape macrosetae count less than 5; head length typically <0.59 mm (HL: 0.47–0.59); usually bicolored with darker head and gaster (fig. 55)................................................................................... wojciki

12. Scape macrosetae absent............................................................................... 13

- Scape macrosetae present.............................................................................. 14

13. Overall brown in color, with yellowish scapes contrasting with head color (fig. 35)............................. parvula

- Overall yellow in color, with yellowish scapes not contrasting with head color (fig. 50)......................... trageri

14. Overall moderate to dark brown, with mesocoxae and metacoxae not strongly contrasting with mesosoma; moderate to dense cephalic pubescence; with a dense, neat band of pubescence along the dorsal margin of propodeum............. concinna

- If brown in color, cephalic pubescence sparse to absent; if yellow in color, cephalic pubescence moderate to dense, but pubescence absent on propodeum............................................................................ 15

15. Cephalic pubescence moderate to dense................................................................... 16

- Cephalic pubescence sparse to absent..................................................................... 17

16. Gaster becomes brownish distally; gaster macrosetae densely distributed (fig. 1, 3)........................... arenivaga

- Gaster uniform yellow in color; gaster macrosetae not densely distributed (figs. 40, 42)......................... querna

17. HL at least 0.67 mm; SL at least 0.76 mm; scapes usually with decumbent pubescence (fig. 68); posterior margin of head usually without medial emargination.................................................................. magnella

- HL at most 0.67 mm; SL less than 0.76 mm; scapes usually without decumbent pubescence (figs. 74, 75); posterior margin of head usually with slight medial emargination.............................................................. 18

18**. Head with subparallel lateral margins in full face view (fig. 53), appearing relatively squarish; typically REL> 24... vividula

- Head with convex lateral margins in full face view (fig. 47), appearing relatively ovate; typically REL<24........ terricola