Key to Polyrhachis (Hagiomyrma) species

The following key to Polyrhachis (Hagiomyrma) species (based on the worker caste) is modified from Kohout (2013 ) as updated by Hoffmann (2015 ).

1

 * Generally larger species (HL > 2.20) => 2
 * Generally medium-sized or small species (HL < 2.15) => 14

2

 * Pronotal dorsum with margins strongly converging anteriorly (Fig. 5A); occipital corners with distinct postocular carinae; anterior clypeal margin deeply emarginate medially (New Guinea and Bismarck Archipelago) => Polyrhachis metella
 * Pronotal dorsum more-or-less quadrate or only weakly converging anteriorly (e.g. Figs 2E, 4A); occipital corners simply rounded, without postocular carinae; anterior clypeal margin medially with denticulate flange or simply truncate => 3

3

 * Gaster with pubescence very much diluted, virtually lacking; head and mesosoma with long, rich golden pubescence (Fig. 4C-D) (QLD, NSW, VIC) => Polyrhachis semiaurata
 * Gaster with golden or silvery pubescence identical or similar to that on dorsum of head and mesosoma => 4

4

 * Pronotal humeri distinctly angular (Fig. 4G); dorsum of first gastral tergite strongly tranverse, laterally produced into narrowly rounded prominences (Cape York Pen., Mt Tozer, QLD) => Polyrhachis vernoni
 * Pronotal humeri narrowly or widely rounded (e.g. Fig. 2C, E); dorsum of first gastral tergite less transverse, with sides widely rounded => 5

5

 * Petiolar node relatively thick in profile with dorsum widely rounded or forming more-or-less flat platform; petiolar spines short, bases situated well below summit of dorsal convexity (Figs 2F, 13B) => 6
 * Petiolar node in profile with anterior and posterior face converging towards narrowly rounded dorsum; petiolar spines longer, bases situated at lateral corners of dorsal summit (e.g. Fig. 1B, H) => 7

6

 * Pronotal dorsum with margins weakly converging anteriorly; propodeal spines subparallel (Fig. 13A); head in full face view with numerous hairs fringing lateral outline between eyes and mandibular bases (Cape York Pen., McIlwraith Range, QLD) => Polyrhachis darlingtoni
 * Pronotal dorsum more-or-less quadrate; propodeal spines divergent (Fig. 2E) head in full face view with no hairs fringing lateral outline between eyes and mandibular bases (Mt Abbott, QLD) => Polyrhachis burwelli

7

 * Dorsum of gaster with golden or silvery pubescence and more-or-less distinct, dark reddish-brown, median patch, extending from dorsum of first gastral tergite towards apex (e.g. Fig. 2C, G) => 8
 * Dorsum of gaster with widely diffused patch of golden pubescence extending towards apex; reddish-brown median patch on gaster not evident (e.g. Figs 1A-B, 4E-F) => 12

8

 * Median patch on gastral dorsum very dark and prominent (Figs 2G, 3A) => 9
 * Median patch on gastral dorsum lighter and less prominent (e.g. Figs 2C, 4A) => 10

9

 * Dorsum of pronotum with only a few, relatively short, erect hairs; hairs completely absent from mesonotum, propodeum, including declivity, and propodeal spines (Fig. 3A-B) (central QLD) => Polyrhachis conciliata
 * Dorsum of mesosoma, including bases of propodeal spines, with numerous erect or semierect, long or medium length hairs (central QLD) => Polyrhachis callima

10

 * Pronotal dorsum with margins weakly converging anteriorly (Fig. 4A) (Cooktown district, QLD) => Polyrhachis feehani
 * Pronotal dorsum more-or-less quadrate or weakly converging posteriorly (e.g. Fig. 2A, C) => 11

11

 * Smaller species (HL 2.18-2.37); clypeus virtually straight in profile; dorsa of head and mesosoma with rich golden pubescence, radiating towards midline of mesosoma (Fig. 2A-B) (Brisbane district, QLD) => Polyrhachis brisbanensis
 * Larger species (HL 2.28-2.62); clypeus sinuate in profile; dorsa of head and mesosoma with pubescence mostly silvery, diffused into pale golden along midline of mesosoma (Fig. 2C-D) (central QLD) => Polyrhachis brutella

12

 * Petiolar spines subparallel, shorter than distance between their bases; dorsa of head and mesosoma with evenly distributed golden pubescence => 13
 * Petiolar spines divergent, about as long as or longer than distance between their bases; body pubescence unevenly distributed with head distinctly less pubescent than dorsum of mesosoma (Fig. 1A-B) (QLD, NSW, VIC) => Polyrhachis ammon

13

 * Smaller species (HL 2.02-2.24); propodeal spines widely divergent; petiolar spines strongly downturned (Fig. 4E-F) (QLD) => Polyrhachis uncaria
 * Larger species (HL 2.21-2.40); propodeal spines subparallel; petiolar spines more-or-less horizontal (Fig. 3E-F) (Hann Tbld, QLD) => Polyrhachis dougcooki

14

 * Dorsum of mesosoma distinctly short and wide; propodeal spiracles situated on prominent, laterally projecting tubercles; petiolar dorsum strongly transverse, armed with very short spines => 15
 * Dorsum of mesosoma more-or-less elongated; propodeal spiracles relatively flat, not situated on prominent tubercles; petiolar dorsum armed with spines of various lengths => 16

15

 * Head and mesosoma with distinct, closely appressed, golden pubescence; dorsum of gaster with only a few, medium length hairs and no pubescence (Fig. 14A-B) (Cape York Pen., QLD) => Polyrhachis diversa
 * Head and mesosoma without appressed pubescence; dorsum of gaster with very fine, closely appressed, pale golden pubescence (Fig. 14C-D) (QLD) => Polyrhachis tubifera

16

 * Head and mesosoma generally black, with only mouthparts, pronotal collar, spines and appendages occasionally reddish brown => 24
 * Head and mesosoma not black, coloured or multi-coloured (e.g. Figs 11E-F, 12C-D) => 17

17

 * Lateral margins of promesonotum strongly converging posteriorly (PMI > 190) (e.g. Fig. 12G) => 18
 * Lateral margins of promesonotum less strongly converging posteriorly (PMI < 180) (e.g. Fig. 11C) or subparallel => 20

18

 * Generally smaller species (HL 1.31-1.56); antennal scapes virtually circular in crosssection; dorsum of gaster with distinct, thick silvery or golden, appressed pubescence (Fig. 12G-H) (New Guinea, WA, NT, QLD) => Polyrhachis schenckii
 * Generally larger species (HL 1.53-1.75); antennal scapes somewhat flattened, oval in cross-section; appressed pubescence on dorsum of gaster very sparse or lacking => 19

19

 * Antennal scapes relatively short (SI 123); greatest width of pronotal dorsum near its mid-length; propodeal spines obliquely elevated from bases (Fig. 11G-H) (NT) => Polyrhachis isolata
 * Antennal scapes relatively long (SI 134-143); greatest width of pronotal dorsum across humeri; propodeal spines horizontal (Fig. 11E-F) (Cape York Pen., QLD) => Polyrhachis injinooi

20

 * Head, mesosoma and gaster metallic green, with front of head, anterior portion of pronotum and appendages orange or reddish-brown (Fig.12C-D) (QLD) => Polyrhachis lydiae
 * Head, mesosoma and gaster not metallic green, mostly medium to dark reddish brown or red with gaster distinctly darker => 21

21

 * Head and mesosoma conspicuously red or orange-red; gaster very dark brown; appendages reddish-brown (Fig. 11A-B) (WA, NT, QLD) => Polyrhachis bohemia
 * Head and mesosoma almost uniformly medium to dark reddish- brown with gaster usually a shade lighter; appendages reddish-brown => 22

22

 * Pronotal humeri produced into dilated, dorsally shallowly concave, rounded prominences (Fig. 12A, E); head and mesosoma with more-or-less distinct, vermiculate sculpturation => 23
 * Pronotal humeri narrowly rounded; body sculpturation reticulate- punctate, not vermiculate (Fig. 11C) (Cape York Pen., QLD) => Polyrhachis capeyorkensis

23

 * Head and mesosoma reticulate-punctate, shallowly vermiculate- rugose on vertex of head and dorsum of mesosoma; colour almost uniformly medium reddish-brown, appendages and spines a shade lighter (Fig. 12A-B) (QLD) => ''[[Polyrhachis lachesis Forel
 * Head and mesosoma with very distinct, vermiculate-rugose sculpturation; colour mostly black or very dark reddish-brown on most dorsal surfaces; appendages and spines distinctly lighter (Figs 12E-F) (Indonesia, New Guinea, Cape York, QLD) => Polyrhachis paxilla

24

 * Antennal scapes with at least a few short, bristle-like hairs along leading edge => 25
 * Antennal scapes without any hairs along leading edge => 35

25

 * Promesonotal lateral margins only very weakly converging posteriorly (PMI < 140); petiole in lateral view rather low with very short, curved spines (Fig. 13C-D) (NT) => Polyrhachis nourlangie
 * Promesonotal lateral margins more strongly converging posteriorly (PMI > 150); petiole in lateral view distinctly higher with longer spines of various configurations => 26

26

 * Outline of head in full face view without hairs, or at most with only a few inconspicuous, very short hairs fringing margin between eyes and mandibular bases => 27
 * Outline of head in full face view with numerous bristle-like hairs fringing margin between eyes and mandibular bases => 27a

27

 * Head, mesosoma and petiole very distinctly and evenly, rather coarsely, reticulate-punctate; petiole in profile with posterior face distinctly convex and swollen towards base [Figs 19G-H] (Nth Qld) => Polyrhachis tenebra
 * Head, mesosoma and petiole finely reticulate-punctate with sculpture somewhat longitudinally rugulate-striate on vertex of head; petiole in profile with posterior face only weakly convex [Figs 9A-B] (New Ireland, New Guinea, Cape York Peninsula) => Polyrhachis semiobscura

27a

 * Petiole armed with rather massive, bull horn-shaped spines (Fig. 2) (NT only) => Polyrhachis kohouti
 * Petiole armed with slender, acute spines, mostly curved into shape of first gastral segment or downcurved [e.g. Figs 9C, 19A] => 28

28

 * Petiolar spines distinctly downcurved, hook-like (Fig. 1D) (only WA) => Polyrhachis ammonoeides
 * Petiolar spines more-or-less horizontal or obliquely elevated, never hook-like (e.g. Figs 9D, 10B) => 29

29

 * Promesonotal lateral margins distinctly converging posteriorly (PMI > 190) (e.g. Figs 9C, 10A) => 30
 * Promesonotal lateral margins less strongly converging posteriorly (PMI < 180) (e.g. Fig. 12E) => 31

30

 * Antennal scapes relatively short (SI < 141); petiole in profile with posterior face only weakly convex towards base (Fig. 9C-D) (Nth QLD) => Polyrhachis stricta
 * Antennal scapes relatively long (SI > 154); petiole in profile distinctly swollen towards base (Fig. 10A-B) (NT) => Polyrhachis weiri

31

 * Pronotal dorsum with humeri produced into dilated, distinctly rounded prominences (Fig. 12E-F); head and mesosoma with distinct, vermiculate sculpturation (Indonesia, New Guinea, Cape York) => Polyrhachis paxilla
 * Pronotal dorsum with humeri rounded or subangular, not distinctly dilated; head and mesosoma reticulate-punctate => 32

32

 * Petiolar node in profile with posterior face distinctly swollen towards base (Fig. 10B); clypeus in profile virtually straight or only very shallowly impressed anteriorly => 33
 * Petiolar node in profile with posterior face not distinctly swollen, descending towards base in weakly convex line; clypeus in profile distinctly sinuate (Fig. 8E-F) (Nth QLD) => Polyrhachis placida

33

 * Dorsum of gaster with distinct, closely appressed, golden pubescence, completely hiding underlying sculpturation (Fig. 8CD) (Pilbara, WA) => Polyrhachis pilbara
 * Dorsum of gaster with much diluted, silvery or golden, appressed pubescence (Fig. 11A-B) => 34

34

 * Dorsum of mesosoma with very short, erect, bristle-like hairs (Fig. 8G-H) (Barrow I., WA) => Polyrhachis seducta
 * Dorsum of mesosoma with distinctly longer, posteriorly directed hairs that are up to half greatest diameter of eyes in length (Fig. 9E-F) (Tanami Desert, NT) => Polyrhachis tanami

35

 * Promesonotal lateral margins strongly converging posteriorly (PMI > 185) (e.g. Figs 1G, 13G) => 36
 * Promesonotal lateral margins less strongly or weakly converging posteriorly (PMI < 180) (e.g. Fig. 3C, 13E) => 37

36

 * Dorsum of petiole with flat, strongly posteriorly sloping, triangular platform; petiolar spines obliquely elevated; propodeal spines subparallel or only weakly divergent; antennal scapes relatively short (SI < 142) (Fig. 13G-H) (NT, QLD) => Polyrhachis trapezoidea
 * Dorsum of petiole narrowly rounded, without flat platform; petiolar spines horizontal; propodeal spines widely divergent; antennal scapes longer (SI > 160) (Fig. 1G-H) (Paluma, Mt Elliot) => Polyrhachis aurora

37

 * Propodeal spines strongly divergent and long, distinctly longer than distance between their bases (Fig. 3C) => 38
 * Propodeal spines less strongly divergent or subparallel, distinctly shorter than distance between their bases (Fig. 13E) => 39

38

 * Dorsum of body without hairs, except a few, short hairs on apical gastral tergites; closely appressed pubescence very diluted with whole body superficially glabrous (Fig. 3CD) (NT, Nth QLD) => Polyrhachis cracenta
 * Dorsum of mesosoma with rather sporadic hairs of various lengths; gaster with hairs more abundant, notably on venter; appressed, golden pubescence diluted on most body surfaces, except rather dense on gastral dorsum (Fig. 6G-H) (WA, NT, Nth QLD) => Polyrhachis crawleyi

39

 * Dorsum of petiole with flat, transversely wide platform; dorsum of body with very abundant, long silvery hairs that are distinctly longer than greatest diameter of eyes; antennal scapes very short (Fig. 13EF) (SI < 125) (Cape York Pen., Nth QLD) => Polyrhachis thusnelda
 * Dorsum of petiole narrowly rounded without flat platform; body with relatively short, erect hairs or, at most, with only sporadic, variously curved, longer hairs (as in Polyrhachis hoffmanni and Polyrhachis denticulata); antennal scapes longer (SI > 125) => 40

40

 * Dorsum of head and mesosoma with distinct, rather abundant, mostly golden, medially radiating pubescence => 41
 * Dorsum of head and mesosoma with rather diluted, mostly silvery, variously scattered pubescence => 45

41

 * Petiolar node in side view with anterior and posterior faces subparallel towards base; antennal scapes rather short (Fig. 7CD) (SI < 137) (Nth QLD) => Polyrhachis electra
 * Petiolar node in side view with anterior and posterior faces converging dorsally; posterior face descending towards base in oblique, almost straight line => 42

42

 * Dorsum of mesosoma distinctly slender (PMI > 167); propodeal spines obliquely elevated from bases; petiolar spines widely divergent, very slender and long, about as long as distance between their bases (Fig. 1E-F) (QLD, NSW) => Polyrhachis angusta
 * Dorsum of mesosoma not distinctly slender (PMI < 167); propodeal spines more-or-less horizontal or weakly down turned; petiolar spines subparallel or only weakly divergent, distinctly shorter than distance between their bases => 43

43

 * Petiolar spines divergent, obliquely elevated from bases; propodeal spines virtually parallel along entire length (Fig. 3G-H) (Nth QLD) => Polyrhachis elegantula
 * Petiolar spines only weakly divergent or subparallel, horizontal or downturned; propodeal spines weakly divergent with tips curved outwards => 44

44

 * Petiolar spines horizontal; dorsum of gaster with wide median patch of golden pubescence, laterally diffused into pale golden and silvery on sides and venter (Fig. 1A-B) => Polyrhachis ammon
 * Petiolar spines strongly downturned from bases; whole dorsum of gaster with distinct, reddish-golden pubescence, lined with silvery pubescence on sides and venter (Fig. 4E-F) => Polyrhachis uncaria

45

 * Dorsum of mesosoma with rather long, variously curved, scattered hairs; hairs more abundant and posteriorly directed on gaster => 46
 * Dorsum of mesosoma virtually lacking hairs or with only very short, much diluted hairs on dorsal body surfaces, including gaster => 47

46

 * Promesonotal lateral margins strongly converging posteriorly (PMI > 170); body with variously curved, scattered hairs that are longer than half of greatest diameter of eyes; posterior face of petiolar node convex, but not distinctly swollen (Fig. 7A-B) (Indonesia, New Guinea, Bismarck Archipelago, Torres Strait) => Polyrhachis denticulataKaravaiev.
 * Promesonotal lateral margins rather weakly converging posteriorly (PMI < 145); body with variously curved hairs, most longer than greatest diameter of eyes; posterior face of petiolar node distinctly swollen towards base (Fig. 7E-F) (Nth western QLD) => Polyrhachis hoffmanni

47

 * Dorsum of petiole tranversely narrow, rather deeply concave between closely approximated bases of spines => 48
 * Dorsum of petiole flat or very weakly concave; bases of spines separated by transversely wide dorsum of segment => 50

48

 * Petiolar spines widely divergent, highly obliquely elevated; propodeal spines very slender, divergent; posterior face of petiolar node convex but not distinctly swollen (Fig. 6E-F) (Geraldton, WA) => Polyrhachis clarki
 * Petiolar spines parallel or only weakly divergent, moderately elevated; propodeal spines subparallel; posterior face of petiolar node distinctly swollen towards base => 49

49

 * Smaller species (HL < 1.62); anterior clypeal margin truncate medially; bases of petiolar spines very closely approximated, spines subparallel; body sculpture very finely reticulate-punctate, semi- polished (Fig. 6A-B) (WA, NT) => Polyrhachis anderseni
 * Larger species (HL > 1.62); anterior clypeal margin with denticulate median flange; bases of petiolar spines more widely separated, spines weakly; body sculpture closely reticulate-punctate, distinctly opaque (Fig. 6C-D) (NT, Gulf Country, QLD) => Polyrhachis archeri

50

 * Petiole with posterior face distinctly swollen towards base; petiolar spines elevated from bases; head and mesosoma with rather sporadic, very short, bristlelike hairs, no hairs on dorsum of petiole; body sculpture closely reticulate- punctate, distinctly opaque (Fig. 7G-H) (WA, NT, QLD) => Polyrhachis melanura
 * Petiole with posterior face only moderately convex towards base; petiolar spines horizontal; head, mesosoma and petiole with more abundant, marginally longer hairs; body sculpture finely reticulatepunctate, semi-polished (Fig. 8A-B) (Nth and Central QLD) => Polyrhachis penelope