Key to Ant Genera of the Navajo Reservation

AntWiki: The Ants --- Online

This key to workers is based on

At present 24 ant genera are known within the Navajo Reservation, as additional ant genera are discovered, they will be added to the key below. Each Navajo genus page links to a Navajo species level key for workers on the Navajo Reservation and each species page will then link to the AntWiki species page.


1

  • Petiole and postpetiole present (pedicel has two segments) . . . . . 2
Profile of Veromessor smithi worker
Profile of Pogonomyrmex imberbiculus worker
Profile of Temnothorax carinatus worker
  • Petiole present (pedicel has one segment), postpetiole absent or not well separated from remainder of gaster . . . . . 3
Profile of Hypoponera opacior worker
Profile of Formica neorufibarbis worker
Profile of Dorymyrmex insanus worker

2 (1)

  • Antennal sockets completely exposed in full-face view, not covered by frontal lobes. Antennal sockets positioned close to each other and inserted at the anterior margin of the head. Eyes absent or extremely small (Subfamily Ecitoninae) . . . . . Neivamyrmex (2 species)
Frontal view of Neivamyrmex nyensis worker
Frontal view of Neivamyrmex opacithorax worker
  • In full-face view antennal sockets covered at least in part by frontal lobes. Antennal sockets well separated and set back from the anterior margin of the head. Eyes present with several facets or more. (Subfamily Myrmicinae) . . . . . 5
Frontal view of Crematogaster larreae worker
Frontal view of Veromessor lobognathus worker

3 (1)

  • No postpetiole, petiole clearly separated from remainder of gaster; sting absent. . . . . . 4
Lateral view of Camponotus ocreatus worker
Lateral view of Formica aserva worker
Dorsal view of Liometopum luctuosum worker
  • Postpetiole with a slight separation from remainder of gaster; sting present; Subpetiolar process simple lobe, never with fenestra or paired posterolateral teeth. Anterior border of clypeus without teeth; mandible relatively small (Subfamily Ponerinae). . . . . Hypoponera opacior
Frontal view of Hypoponera opacior worker
Lateral view of Hypoponera opacior worker
Dorsal view of Hypoponera opacior worker

4 (3)

  • Acidopore absent, no ring of hairs at apex of gaster (Subfamily Dolichoderinae) . . . . . 15
  • Acidopore at apex of gaster round and usually surrounded by ring of hairs (Subfamily Formicinae) . . . . . 18

5 (2)

  • Antennae with 10 segments, last 2 segments forming a distinct club; propodeum without spines; either dimorphic species or very small monomorphic species . . . . . Solenopsis (2 species)
Frontal view of Solenopsis xyloni major
Lateral view of Solenopsis xyloni major
Dorsal view of Solenopsis xyloni worker


6 (5)

  • Postpetiole connected to dorsal surface of gaster; gaster, when seen from above, heart shaped with pointed apex; pronotum without spines or bumps . . . . . Crematogaster (3 species)
Lateral view of Crematogaster larreae worker
Lateral view of Crematogaster depilis worker
Dorsal view of Crematogaster navajoa worker
  • Postpetiole not connected to upper surface of gaster; gaster not heart shaped . . . . . 7

7 (6)

  • Eyes with short, erect hairs emerging from facets (use high magnification)(Found inside the nests of Formica ravida)...Formicoxenus hirticornis
Frontal view of Formicoxenus hirticornis worker
Lateral view of Formicoxenus hirticornis worker
Dorsal view of Formicoxenus hirticornis worker
  • Eyes lacking erect hairs..... 8

8 (7)

  • Mandible with six teeth. Clypeus not forming welt; frontal carinae do not extend to posterior border of head . . . . . Leptothorax (3 species)
Frontal view of Leptothorax crassipilis worker
Lateral view of Leptothorax crassipilis worker
Dorsal view of Leptothorax crassipilis worker
Frontal view of Temnothorax carinatus worker
Lateral view of Temnothorax carinatus worker
Dorsal view of Temnothorax carinatus worker

9 (5)

  • Middle and hind tibial spurs pectinate (with tiny hairs, difficult to see without at least 60x magnification) . . . . . 10

10 (9)

  • Metanotal constriction (between mesonotum and propodeum) absent, propodeum often with spines or teeth, psammophore (long curved hairs on underside of head) usually present; common in arid ecosystems . . . . . Pogonomyrmex /(Key to 6 species)
Dorsal view of Pogonomyrmex maricopa worker
Lateral view of Pogonomyrmex imberbiculus worker
Lateral view of Pogonomyrmex rugosus worker
  • Metanotal constriction present between mesonotum and propodeum , propodeum always has spines; psammophore absent; common in pine forests and mountainous areas. . . . . . Myrmica / (5 species)
Dorsal view of Myrmica brevispinosa worker
Lateral view of Myrmica rugiventris worker
Lateral view of Myrmica tahoensis worker

11 (9)

  • Propodeum without spines; antennal club composed of 3 segments; usually small, shiny, black ants . . . . . Monomorium (2 species)
Frontal view of Monomorium cyaneum worker
Lateral view of Monomorium cyaneum worker
Dorsal view of Monomorium cyaneum worker
  • Propodeum with spines or teeth; antennal club configuration varies . . . . . 12

12 (11)

  • Psammophore present... Messor (2 species)
Frontal view of Veromessor lobognathus worker
Lateral view of Veromessor lobognathus worker
Dorsal view of Veromessor lobognathus worker
Lateral view of Aphaenogaster huachucana worker
Lateral view of Stenamma californicum worker
Lateral view of Pheidole hyatti worker

13 (12)

  • Workers dimorphic or polymorphic; major with head longer than gaster; petiole with long peduncle; scape of antenna of minor often extends past posterior border of head; mandible with 2 well defined teeth at apex; . . . . . Pheidole / (8 species)
Frontal view of Pheidole hyatti worker
Lateral view of Pheidole hyatti worker
Dorsal view of Pheidole hyatti worker
  • Monomorphic species; scape does not extend past posterior lateral border of head . . . . . 14

14 (13)

  • Clypeus usually with pair of longitudinal carinae; mesosoma thickened with little constriction between mesonotum and propodeum . . . . . Stenamma / (3 species)
Frontal view of Stenamma snellingi worker
Lateral view of Stenamma snellingi worker
Dorsal view of Stenamma snellingi worker
  • Clypeus without carinae or with more than 1 pair; mesosoma slender . . . . . Aphaenogaster (2 species)
Frontal view of Aphaenogaster huachucana worker
Lateral view of Aphaenogaster huachucana worker
Dorsal view of Aphaenogaster huachucana worker

15 (4)

  • Propodeum in form of cone; maxillary palps very long . . . . . Dorymyrmex (4 species)
Frontal view of Dorymyrmex bicolor worker
Lateral view of Dorymyrmex bicolor worker
Dorsal view of Dorymyrmex bicolor worker

16 (15)

  • Node of petiole poorly developed; monomorphic ants, widely distributed in mesic areas . . . . . Tapinoma sessile
Frontal view of Tapinoma sessile worker
Lateral view of Tapinoma sessile worker
Dorsal view of Tapinoma sessile worker
  • Node of petiole obvious, although it may be small; common ants . . . . . 17

17 (16)

  • Workers polymorphic; mesosoma in profile without impression before posterior edge of propodeum; ocelli present at least in larger workers; gaster with gray pubescence; nests usually in oak trees or under stones in mountainous areas . . . . . Liometopum (2 species)
Frontal view of Liometopum apiculatum worker
Lateral view of Liometopum apiculatum worker
Dorsal view of Liometopum apiculatum worker
  • Erect hairs on clypeus long, extending to near tips of mandibles, when mandibles are shut; pronotum with at least I pair of long, erect hairs (may be missing in some specimens in nest series); Workers monomorphic; ocelli absent; nesting in soil most common in desert regions (also common in urban areas) . . . . . Forelius pruinosus
Frontal view of Forelius pruinosus worker
Lateral view of Forelius pruinosus worker
Dorsal view of Forelius pruinosus worker

18 (4)

  • Antenna with 9 segments; small, light colored, inconspicuous ants, not commonly collected . . . . . Brachymyrmex depilis
Frontal view of Brachymyrmex depilis worker
Lateral view of Brachymyrmex depilis worker
Dorsal view of Brachymyrmex depilis worker

19 (18)

Frontal view of Polyergus mexicanus worker
Lateral view of Polyergus mexicanus worker
Dorsal view of Polyergus mexicanus worker
  • Mandibles not long and sickle shaped, common ants . . . . . 20

20 (19)

  • Insertions of antennae located far from posterior border of clypeus; mesosoma convex (except for C. hyatti) in profile . . . . . Camponotus (6 species)
Frontal view of Camponotus laevissimus worker
Lateral view of Camponotus hyatti worker
Lateral view of Camponotus ocreatus worker
  • Insertions of antennae located near posterior border of clypeus; mesosoma not convex in profile . . . . . 21
Frontal view of Myrmecocystus mexicanus worker
Lateral view of Myrmecocystus mexicanus worker
Lateral view of Formica aserva worker

21 (20)

  • Maxillary palps very long, segment 4 as long as segments 5 and 6 combined; psammophore present . . . . . Myrmecocystus (6 species)
Frontal view of Myrmecocystus mendax worker
Lateral view of Myrmecocystus mendax worker
Lateral view of Myrmecocystus mendax worker
  • Maxillary palps shorter, segment 4 not unusually long; psammophore absent . . . . . 22

22 (21)

  • Frontal carinae prominent, lateral margins slightly reflected upward; ocelli often distinct; mostly large, polymorphic . . . . . Formica (17 species)
Frontal view of Formica densiventris worker
Lateral view of Formica densiventris worker
Dorsal view of Formica densiventris worker
  • Frontal carinae poorly marked, lateral margins flat; ocelli indistinct or absent; smaller monomorphic ants. Maxillary palps short and composed of 3 segments (subgenus Acanthomyops), maxillary palps longer and composed of 6 segments . . . . . Lasius (12 species)
Frontal view of Lasius fallax worker
Lateral view of Lasius fallax worker
Dorsal view of Lasius fallax worker