Key to Pheidole majors of Borneo

Every Ant Tells a Story - And Their Stories Are Here
Jump to navigation Jump to search

This worker key is based on: Eguchi, K. 2001a. A revision of the Bornean species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae). Tropics Monograph Series. 2:1-154. PDF

Because the major of P. gombakensis sp. nov. has not been collected from Borneo, the major from Ulu Gombak, southern Malay Peninsula are used for making the keys “A” and “C.”

You may also be interested in

1

  • Antenna with 5-segmented club, or without conspicuous club . . . . . 2

2

return to couplet #1

  • Apical five antennal segments forming conspicuous club; hypostoma bearing three low median processes; subpetiolar process low, with ventral margin carinate . . . . . 3
  • Antenna lacking conspicuous club; hypostoma lacking distinct median processes; subpetiolar process absent . . . . . 4

3

return to couplet #2

Pheidole quinata.jpg
  • Head in profile not, or only slightly, impressed on vertex . . . . . Pheidole sabahna
Pheidole sabahna.jpg
major
Pheidole sabahna casent0281651 p 1 high.jpg

4

return to couplet #2

  • Dorsum of promesonotal dome in front of the prominence on its posterior declivity bearing 10-20 standing hairs; propodeal spine at least 3.5 times as long as diameter of propodeal spiracle; body light brown to reddish brown . . . . . Pheidole montana
Pheidole montana.jpg
Pheidole montana casent0281649 h 1 high.jpg
Pheidole montana casent0281649 p 1 high.jpg
  • Dorsum of promesonotal dome in front of the prominence on posterior declivity bearing less than 10 standing hairs in Pheidole longipes , or ca. 20 standing hairs in Pheidole comata; propodeal spine usually at most 2.5 times as long as diameter of propodeal spiracle; body reddish brown to dark brown . . . . . 5
Pheidole comata major
Pheidole longipes major

5

return to couplet #4

  • Head densely bearing standing hairs over the surface; lateral face of occipital lobe distinctly rugose; dorsum of promesonotal dome in front of the prominence on its posterior declivity bearing ca. 20 standing hairs . . . . . Pheidole comata
Pheidole comata.jpg
major
Pheidole comata casent0281704 p 1 high.jpg
  • Head with sparse standing hairs only on frons and vertex; lateral face of occipital lobe weakly and finely rugose, or almost smooth and shining; dorsum of promesonotal dome in front of the prominence on its posterior declivity bearing at most 10 standing hairs . . . . . Pheidole longipes
Pheidole longipes.jpg
major
Pheidole longipes casent0281706 p 1 high.jpg

6

return to couplet #1

  • Promesonotum armed with a pair of long and pointed spines; hypostoma always bearing a pair of stout median processes . . . . . 7
  • Promesonotum unarmed, or each dorsolateral portion of promesonotum produced outward (e.g., Pheidole aristotelis), but never armed with long and pointed spines; hypostoma bearing 0-3 median processes . . . . . 11

7

return to couplet #6

  • Gaster smooth and shining over the surface, or only anterior part of first gastral tergite near its articulation with postpetiole weakly punctured; petiolar node in profile acute at apex . . . . . Pheidole acantha
Pheidole acantha.jpg
major
Pheidole acantha casent0901619 p 1 high.jpg
  • At least first gastral tergite punctured or rugoso-punctured and dull over the surface; petiolar node in profile blunt at apex . . . . . 8

8

return to couplet #7

  • Propodeal spine digitiform and blunt apically; alitrunk sparsely covered with relatively short standing hairs . . . . . Pheidole quadricuspis
Pheidole quadricuspis.jpg
major
Pheidole quadricuspis casent0905766 p 1 high.jpg
  • Propodeal spine horn-like or elongate-triangular, pointed apically; alitrunk covered with relatively long standing hairs . . . . . 9

9

return to couplet #8

Pheidole quadrensis.jpg
minor
Pheidole quadrensis casent0281631 p 1 high.jpg

10

return to couplet #9

  • Body larger (e.g., HW 2.79-2.91 mm); subpetiolar process completely absent . . . . . Pheidole lokitae
Pheidole lokitae.jpg
major
Pheidole lokitae casent0281702 p 1 high.jpg
  • Body smaller (e.g., HW 1.73-2.12 mm); petiole with very low subpetiolar process . . . . . Pheidole spinicornis
Pheidole spinicornis.jpg
major
Pheidole spinicornis casent0901621 p 1 high.jpg

11

return to couplet #6

  • Legs from apex of femur to apex of tarsus ivory-white, contrasted with remainder of femur which is dark brown . . . . . Pheidole fantasia
Pheidole fantasia.jpg
major
MCZ-ENT00031796 Pheidole fantasia hal.jpg

12

return to couplet #11

  • Frontal lobe extremely developed, extending beyond anterior margin of clypeus . . . . . Pheidole upeneci
Pheidole upeneci.jpg
major
Pheidole upeneci casent0281684 p 1 high.jpg
  • Frontal lobe sometimes developed, but never extending beyond anterior margin of clypeus . . . . . 13

13

return to couplet #12

  • Eye consisting of 5-7 ommatidia; terminal segment of antenna more than 1.6 times as long as preceding two segments together . . . . . Pheidole parvicorpus
Pheidole parvicorpus.jpg
major
Pheidole parvicorpus casent0281687 p 1 high.jpg
  • Eye consisting of at least 10 ommatidia; terminal segment of antenna at most 1.3 times as long as preceding two segments together . . . . . 14

14

return to couplet #13

  • Frons irregularly reticulate; hypostoma bearing a stout median process; frontal carina horizontal, extensively overhanging antennal scrobe; each dorsolateral portion of promesonotal dome produced outward . . . . . Pheidole aristotelis
Pheidole aristotelis.jpg
major
Pheidole aristotelis casent0219465 p 1 high.jpg
  • Frons longitudinally rugose; hypostoma bearing 0-3 median processes; the condition of frontal carina and antennal scrobe variable; each dorsolateral portion of promesonotal dome sometimes produced outward . . . . . 15

15

return to couplet #14

  • Masticatory margin of mandible having two denticles before basal angle; ventral faces of midcoxa and hindcoxa distinctly reticulate (this condition exclusively shared with Pheidole aristotelis among others) . . . . . 16
  • Masticatory margin of mandible having at most one denticle before basal angle; ventral faces of midcoxa and hindcoxa completely smooth and shining . . . . . 20

16

return to couplet #15

Pheidole clypeocornis.jpg
major
Pheidole clypeocornis casent0281682 p 1 high.jpg
  • Lateral portion of clypeus never developed into a horn . . . . . 17

17

return to couplet #16

  • Outer face of mandible sculptured with rugulae running from its base toward its masticatory margin . . . . . Pheidole rugifera
Pheidole rugifera.jpg
major
Pheidole rugifera casent0901653 p 1 high.jpg
  • Outer face of mandible smooth and shining, or rugose laterally only around its base . . . . . 18

18

return to couplet #17

  • Frons (the area between frontal carinae) reticulate in its posterior part where spaces enclosed by rugulae punctured and dull . . . . . Pheidole tenebricosa
Pheidole tenebricosa.jpg
major
Pheidole tenebricosa casent0901659 p 1 high.jpg
  • Frons longitudinally rugose or rugoso-reticulate in its posterior part where spaces enclosed by rugulae almost smooth and shining . . . . . 19

19

return to couplet #18

Pheidole hortensis.jpg
major
Pheidole hortensis casent0179654 p 1 high.jpg
Pheidole kikutai.jpg
major
Pheidole kikutai casent0901649 p 1 high.jpg

20

return to couplet #15

  • Frontal carina horizontal, extensively overhanging antennal scrobe; hypostoma always bearing one large median process . . . . . 21
  • Frontal carina sometimes well developed, but not overhanging antennal scrobe extensively; hypostoma bearing 0-3 median processes . . . . . 23

21

return to couplet #20

Pheidole retivertex.jpg
major
Pheidole retivertex casent0179656 p 1 high.jpg

22

return to couplet #21

  • Frontal lobe well developed and suberect; frons sparsely covered with longitudinal rugulae . . . . . Pheidole tjibodana
Pheidole tjibodana.jpg
major
Pheidole tjibodana casent0281725 p 1 high.jpg
  • Frontal lobe poorly developed; frons densely covered with longitudinal rugulae ...... . . . . . Pheidole sayapensis
Pheidole sayapensis.jpg
major
Pheidole sayapensis casent0901655 p 1 high.jpg

23

return to couplet #20

  • Each dorsolateral portion of promesonotum produced as a stout horn; eye small (distance between mandibular insertion and anterior margin of eye 2.1-2.6 times as long as maximal diameter of eye); postpetiole broad (2.3-2.8 times as broad as petiolar node) . . . . . Pheidole angulicollis
Pheidole angulicollis.jpg
major
Pheidole angulicollis casent0281626 p 1 high.jpg
  • Each dorsolateral portion of promesonotum sometimes produced but not forming a stout horn; eye variable in size (distance between mandibular insertion and anterior margin of eye usually less than twice as long as maximal diameter of eye); postpetiole variable in width (usually less than 2.3 times as broad as petiolar node) . . . . . 24

24

return to couplet #23

  • Petiolar node in profile highly prominent; hypostoma always bearing a pair of median processes; occasionally the processes poorly developed in P. elisae Emery); mesopleuron divided by a transverse impression into two parts, of which lower part is always margined dorsally; alitrunk, or at least its large part, smooth and shining . . . . . 25
  • Petiolar node in profile usually poorly prominent (with exceptions as seen in Pheidole bugi, in which, however, hypostoma bears three similar-sized median processes); when mesopleuron divided by a transverse impression into two parts, lower part is usually not margined dorsally (with exceptions as seen in Pheidole poringensis, in which alitrunk is reticulate) . . . . . 27

25

return to couplet #24

  • Dorsum of head completely covered with longitudinal rugulae . . . . . Pheidole sauberi
Pheidole sauberi.jpg
major
Pheidole sauberi casent0219512 p 1 high.jpg

26

return to couplet #25

Pheidole elisae.jpg
major
Pheidole elisae casent0281689 p 1 high.jpg
Pheidole sarawakana.jpg
major
Pheidole-sarawakanaL4.jpg

27

return to couplet #24

Pheidole huberi.jpg
major
Pheidole huberi casent0281710 p 1 high.jpg

28

return to couplet #27

Pheidole modiglianii.jpg
major
Pheidole modiglianii casent0281712 p 1 high.jpg
  • Propodeal spine at most slightly passing posterior end of propodeal lobe . . . . . 29

29

return to couplet #28

  • Dorsum of occipital lobe smooth and shining (or only weakly and sparsely rugose in Pheidole manukana where postpetiole 2.4-2.6 times as broad as petiolar node) . . . . . 30
  • Dorsum of head including that of occipital lobe completely sculptured (or rugulae on occipital lobe weak in Pheidole orophila sp. nov. where, however, postpetiole 1.6-1.7 times as broad as petiolar node) . . . . . 36

30

return to couplet #29

  • Hypostoma always lacking median processes; petiole less than 1.2 times as long as postpetiole . . . . . 31
  • Hypostoma bearing 1-3 median processes; (in part of Pheidole lucioccipitalis hypostoma lacks all the median processes where petiole is more than 1.5 times as long as postpetiole) . . . . . 33

31

return to couplet #30

  • Distance between mandibular insertion and anterior margin of eye ca. 2.3-2.4 times as long as maximal diameter of eye . . . . . Pheidole havilandi
Pheidole havilandi.jpg
major
Pheidole havilandi casent0281718 p 1 high.jpg
  • Distance between mandibular insertion and anterior margin of eye 1.4-1.6 times as long as maximal diameter of eye . . . . . 32

32

return to couplet #31

  • Postpetiole 2.4-2.6 times as broad as petiolar node; frontal carina conspicuous . . . . . Pheidole manukana
Pheidole manukana.jpg
major
Pheidole manukana casent0901633 p 1 high.jpg
  • Postpetiole 1.8-1.9 times as broad as petiolar node; frontal carina inconspicuous . . . . . Pheidole megacephala
major
Pheidole megacephala iccdrs0003685 profile 1.jpg

33

return to couplet #30

  • Posterior declivity of promesonotal dome having a distinct prominence . . . . . Pheidole plinii
Pheidole plinii.jpg
major
Pheidole plinii casent0281663 p 1 high.jpg
  • Posterior declivity of promesonotal dome lacking a distinct prominence . . . . . 34

34

return to couplet #33

  • Hypostoma bearing an indistinct median process, or lacking median process; clypeus having a median longitudinal carina . . . . . Pheidole lucioccipitalis
Pheidole lucioccipitalis.jpg
major
Pheidole lucioccipitalis casent0901645 p 1 high.jpg
  • Hypostoma bearing 2-3 median processes; clypeus lacking a conspicuous median longitudinal carina . . . . . 35

35

return to couplet #34

Pheidole deltea.jpg
major
Pheidole deltea casent0901641 p 1 high.jpg
Pheidole merimbun.jpg
major
Pheidole merimbun casent0901635 p 1 high.jpg

36

return to couplet #29

  • Posterior declivity of promesonotal dome lacking a distinct prominence; if the declivity has an inconspicuous prominence (as seen in Pheidole poringensis), hypostoma bearing 2-3 distinct median processes . . . . . 37
  • Posterior declivity of promesonotal dome having a distinct prominence; if the declivity has just an inconspicuous prominence (as seen in Pheidole submonticola), hypostoma completely lacking median processes . . . . . 43

37

return to couplet #36

Pheidole tawauensis.jpg
major
Pheidole tawauensis casent0901657 p 1 high.jpg

38

return to couplet #37

  • Posterior margin of head weakly concave in full-face view; dorsum of promesonotum smooth and shining (with several rugulae) . . . . . Pheidole planidorsum
Pheidole planidorsum.jpg
major
Pheidole planidorsum casent0901639 p 1 high.jpg
  • Posterior margin of head strongly concave in full-face view; dorsum of promesonotum sculptured or smooth . . . . . 39

39

return to couplet #38

40

return to couplet #39

major
Pheidole parva casent0055997 p 1 high.jpg
Pheidole butteli.jpg
major
Pheidole butteli casent0907864 p 1 high.jpg

41

return to couplet #39

  • Petiole almost twice as long as postpetiole (excluding helcium); lateral face of promesonotum almost smooth and shining . . . . . Pheidole gombakensis
Pheidole gombakensis.jpg
  • Petiole at most 1.7 times as long as postpetiole (excluding helcium); lateral face of promesonotum sculptured . . . . . 42

42

return to couplet #41

  • Petiole ca. 1.7 times as long as postpetiole (excluding heIcium); outer face of mandible sparsely covered with very short appressed hairs . . . . . Pheidole rabo
Pheidole rabo.jpg
major
Pheidole rabo casent0907989 p 1 high.jpg
  • Petiole 1.3-1.4 times as long as postpetiole (excluding heIcium); outer face of mandible sparsely covered with relatively long decumbent hairs . . . . . Pheidole poringensis
Pheidole poringensis.jpg

43

return to couplet #36

  • Hypostoma bearing three low median processes, of which each lateral one is partly combined with the process just mesal to mandibular insertion . . . . . Pheidole annexa
Pheidole annexa.jpg
major
Pheidole annexa casent0901627 p 1 high.jpg
  • If hypostoma bears 2-3 median processes, then each lateral one is never combined with the process just mesal to mandibular insertion . . . . . 44

44

return to couplet #43

  • Hypostoma bearing a pair of stout median processes ; petiole almost as long as postpetiole which is relatively massive . . . . . Pheidole ghigii
Pheidole ghigii.jpg
major
Pheidole ghigii casent0904268 p 1 high.jpg
  • If hypostoma bears a pair of small or indistinct median processes, then petiole is at least 1.2 times as long as postpetiole . . . . . 45

45

return to couplet #44

  • Propodeal spine elongate-triangular, with broad base; outer face of mandible bearing short or very short, appressed hairs . . . . . 46
  • Propodeal spine horn-like, with narrow base; outer face of mandible usually bearing relatively long, appressed or decumbent hairs . . . . . 47

46

return to couplet #45

  • Antennal scrobe margined below with a conspicuous carina anteriorly; mesopleuron without a distinct transverse impression . . . . . Pheidole cariniceps
Pheidole cariniceps.jpg
major
Pheidole cariniceps casent0281658 p 1 high.jpg
  • Antennal scrobe present only around antennal insertion, and never margined below with a conspicuous carina; mesopleuron divided by a transverse impression into two parts, of which lower part margined dorsally . . . . . Pheidole submonticola
Pheidole submonticola.jpg

47

return to couplet #45

  • Posteriormost part of dorsum of occipital lobe almost transversely rugose . . . . . Pheidole plagiaria
Pheidole plagiaria.jpg
major
Pheidole plagiaria casent0281714 p 1 high.jpg
  • Dorsum of occipital lobe sculptured, but never transversely rugose . . . . . 48

48

return to couplet #46

  • Frontal carina weak; lateral face of occipital lobe smooth or very weakly rugoso-punctured . . . . . Pheidole jacobsoni
major
Pheidole jacobsoni casent0907909 p 1 high.jpg
  • Frontal carina distinct; lateral face of occipital lobe distinctly rugoso-reticulate . . . . . 49

49

return to couplet #48

  • Posterior margin of head strongly concave in full-face view . . . . . Pheidole aglae
Pheidole aglae.jpg
major
Pheidole aglae casent0281668 p 1 high.jpg
  • Posterior margin of head weakly concave in full-face view . . . . . 50

50

return to couplet #49

  • Distance between mandibular insertion and anterior margin of eye 1.3-1.4 times as long as maximal diameter of eye . . . . . Pheidole fervens
Pheidole fervens.jpg
major
Pheidole fervens casent0008638 profile 1.jpg
  • Distance between mandibular insertion and anterior margin of eye 1.7-2.0 times as long as maximal diameter of eye . . . . . Pheidole inornata
Pheidole inornata.jpg
major
Pheidole inornata casent0281670 p 1 high.jpg