Key to Australian Strumigenys Species

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The following key to Australian Strumigenys is based on Bolton (2000[1]).

1

  • Mandibles short, triangular or nearly so, and with teeth along their entire inner margins => 2
  • Mandibles thin, elongate (or in one case short and curved) and with only 2 or 3 (or rarely 4) teeth at their extreme tips => 8

2

  • With head in full face view the leading edge of the scape with a row of conspicuous projecting curved hairs, of which one or more distinctly curves towards the base of the scape => 3
  • With head in full face view the leading edge of the scape lacking projecting hairs that curve toward the base of the scape, all hairs present are curved or inclined toward the scape apex => 4

3

  • Humeral angle of pronotum without a flagellate hair; cephalic dorsum without a transverse row of 4 standing hairs close to occipital margin but with a single short pair at highest point of vertex; pronotum marinate laterally, its dorsum smooth; first gastral tergite without standing hairs => Strumigenys membranifera
  • Humeral angle of pronotum with a flagellate hair; cephalic dorsum with a transverse row of four standing hairs close to occipital margin and also with a single short pair at highest point of vertex; pronotum not marginate laterally, its dorsum densely reticulate-punctate; first gastral tergite with conspicuous standing hairs => Strumigenys karawajewi

4

  • With the head in full face view the upper scrobe margin and the lateral margin of the occipital lobe without freely projecting hairs; any hairs present are short to minute, strongly anteriorly curved and decumbent to closely apprised => Strumigenys shattucki
  • With the head in full face view the upper scrobe margin or the lateral margin of the occipital lobe, or both, with one to many freely projecting hairs; anteriorly curved minute appressed hairs may also be present on part or all of the margin => 5

5

  • With head in full face view and mandibles fully closed much of the length of the basal lamella clearly visible; with mandibles open the lamella longer than high. In full face view the outer curvature of the eye clearly visible. Mandible with 6 teeth. Pronotum not marginate dorsolaterally => 6
  • With head in full face view and mandibles fully closed the basal lamella invisible or at most with its distal margin only visible; with mandibles open the lamella higher than long. In full face view the eyes invisible. Mandible with 5 teeth. Pronotum marginate dorsolaterally => 7

6

  • Cephalic dorsum from posterior margin of clypeus to level of posterior margins of eyes densely clothed with appressed elongate spatulate hairs that are directed anteriorly => Strumigenys anderseni
  • Cephalic dorsum from posterior margin of clypeus to level of posterior margins of eyes without elongate spatulate hairs => Strumigenys peetersi

7

  • Upper scrobe margin lacking flagellate hairs. Pronotal dorsum without flagellate hairs. With petiole in profile the anterior face of the node much shorter than the elongate curved dorsum. Orifice of propodeal spiracle surrounded by a broad, pale cuticular annulus => Strumigenys semicompta
  • Upper scrobe margin with 3 long flagellate hairs. Pronotal dorsum with a pair of long flagellate hairs at the humeral angle and another pair posterolaterally.. With petiole in profile the anterior face of the node and the dorsal subequal in length. Orifice of propodeal spiracle not surrounded by a broad, pale cuticular annulus => Strumigenys flagellata

8

  • Antenna with 4 segments, the first segment of the funiculus not separated from the 2-segmented club => 9
  • Antenna with 6 segments, the first segment of the funiculus separated from the 2-segmented club by two small segments => 10

9

  • Ventrolateral margin of head with a deeply concave U-shaped indentation immediately in front of the eye => Strumigenys anchis
  • Ventrolateral margin of head continuous in front of the eye, without a concave U-shaped indentation => 11

10

  • With petiole in profile the ventral surface without any trace of spongiform tissue; postpetiole in profile with spongiform tissue reduced to narrow collars that fringe the sclerites, without large spongiform lobes either laterally or ventrally => Strumigenys szalayi
  • With petiole in profile the ventral surface with spongiform tissue present, varying from a narrow longitudinal strip to a deep curtain, or composed of one or more conspicuous lobes; postpetiole in profile usually with ventral and/or lateral spongiform lobes distinct, only rarely reduced to collars => 12

11

  • Cephalic dorsum with spatulate to narrowly spoon-shaped hairs; mandibles longer, MI 42, ML greater than maximum width of anterior clypeal margin => Strumigenys bibis
  • Cephalic dorsum with broadly scale-like to orbicular hairs; mandibles shorter, MI 26-32, ML less than maximum width of anterior clypeal margin => 13

12

  • Dorsal (outer) surface of hind basitarsus or tibia, or both, with one or more projecting suberect to erect long fine hairs that are filiform or flagellate and often extremely slender (this specialised pilosity usually also present on middle leg); ground-pilosity simple to spatulate, decumbent to appressed small hairs may also be present => 14
  • Dorsal (outer) surface of hind basitarsus and tibia without projecting suberect to erect long fine hairs, any pilosity present is ground-pilosity, short, simple to spatulate and decumbent to appressed => 15

13

  • Inner margin of mandible, between apicodorsal tooth and spiniform preapical tooth, with a small but acutely conical second (distal) preapical tooth => Strumigenys radix
  • Inner margin of mandible, between apicodorsal tooth and spiniform preapical tooth unarmed, or with a low welt or tubercle, or even a minute denticle, but never with an acutely conical second (distal) preapical tooth => 16

14

  • Spongiform tissue densely present on dorsal and laterodorsal surfaces of propodeum and mesonotum, as well as bordering propodeal declivity; pronotum sharply marginate dorsolaterally => Strumigenys philiporum
  • Spongiform tissue absent from dorsal and laterodorsal surfaces of propodeum and mesonotum, usually present bordering propodeal declivity; pronotum not sharply marginate dorsolaterally => 17

15

  • First gastral sternite densely reticulate-punctate at least basally and laterally; apical fork of mandible without intercalary teeth or denticles; ventral spongiform appendage of postpetiole a narrow collar-like strip; on ventral surface of head the postbuccal groove and preocular impressions confluent, forming a single broad deep transverse trench => Strumigenys opaca
  • First gastral sternite mostly or entirely smooth, at most with some superficially shagreening at base; apical fork of mandible with 1-3 intercalary teeth or denticles; ventral spongiform appendage of postpetiole a deep U-shaped or V-shaped lobe; on ventral surface of head the postbuccal groove forms a transverse impression, the preocular impressions absent or present, when present posterior to and separate from the postbuccal groove => 18

16

  • Promesonotal dorsum with narrowly spatulate hairs that contrast strongly with the orbicular hairs on the cephalic dorsum; occipital margin of head with 4 erect short hairs; pronotal dorsum reticulate-punctate and with superimposed fine longitudinal rugulae => Strumigenys miniteras
  • Promesonotal dorsum with orbicular hairs that are similar to those on the cephalic dorsum but usually somewhat smaller; occipital margin of head without erect short hairs; pronotal dorsum reticulate-punctate, without superimposed fine longitudinal rugulae => 19

17

  • With head in full-face view the upper scrobe margin with two freely laterally projecting fine filiform or flagellate hairs; one apicoscrobal and one anterior to this, at about the level of the eye => 20
  • With head in full-face view the upper scrobe margin with a single freely laterally projecting flagellate hair, in the apicoscrobal position; without a similar hair anterior to this at about the level of the eye => 21

18

  • With head in full-face view the anterior clypeal margin with a conspicuous and sharply incised median U-shaped or V-shaped notch or impression => 22
  • With head in full-face view the anterior clypeal margin usually shallowly convex, transverse, or broadly shallowly and evenly concave, without a sharply incised median notch or impression => 23

19

  • Leading edge of scape distinctly prominent and forming an obtuse angle at about the midlength; standing hairs on first gastral tergite slightly thickened toward their apices; smaller species with broader head and shorter scape, HL 0.40-0.46, CI 78-85, SI 56-61 => Strumigenys emmae
  • Leading edge of scape more or less evenly curved, not forming a prominent obtuse angle at about the midlength; standing hairs on first gastral tergite spatulate or very flattened and expanded apically; larger species with narrower head and longer scape, HL 0.55, CI 71-73, SI 70-73 => Strumigenys sutrix

20

  • Apical antennomere strongly tapered basally, narrowly articulated with the preapical segment; anterior clypeal margin concave; with head in full-face view margins of preocular carinae convex below antennal insertions; large species with long scapes, HL 0.77-0.86, SI 106-114 => Strumigenys varanga
  • Apical antennomere broad basally, broadly articulated with the preapical segment; anterior clypeal margin transverse; with head in full-face view margins of preocular carinae straight below antennal insertions; smaller species with shorter scapes, HL 0.42-0.61, SI less than 90 => 24

21

  • With petiole in profile the lateral spongiform lobe extends forward to the anterior face of the node; propodeal teeth appear spongiform in dorsal view; dorsum and sides of pronotum with very dense fine ground-pilosity, appearing furry => Strumigenys godeffroyi
  • With petiole in profile the lateral spongiform lobe does not extend forward to the anterior face of the node, lobe usually restricted to the posterior third of the node or less; propodeal teeth appear cuticular in dorsal view; dorsum and sides of pronotum with sparse inconspicuous ground-pilosity, not appearing furry => 25

22

  • Mandible without a preapical tooth or at most with a minute , almost affaced, denticle close to the apex => 26
  • Mandible with a single sharply defined preapical tooth => 27

23

  • Pronotal humeral hair present, usually filiform or flagellate but may be short, stubbly and subclavate => 28
  • Pronotal humeral hair absent => 29

24

  • First gastral tergite without a pelt of short decumbent curved pubescent hairs; a number of erect flagellate hairs present; dorsal (outer) surface of hind tibia with 2 erect flagellate hairs; scape shorter, SI 63-69 => Strumigenys yaleopleura
  • First gastral tergite with a pelt of short decumbent curved pubescent hairs that are directed posteromedially; a few longer erect fine hairs also present; dorsal (outer) surface of hind tibia with 0-1 erect flagellate hairs; scape longer, SI 73-80 => Strumigenys zygon

25

  • Ventrolateral margin of head with a concave preocular notch or impression that interrupts the margin immediately in front of the eye; anterior clypeal margin with a median indentation; apical antennal segment constricted basally and forming a very narrow articulation with preapical segment => Strumigenys racabura
  • Ventrolateral margin of head without a preocular notch or impression, the margin continuous to the eye; anterior clypeal margin shallowly convex to transverse, without a median indentation; apical antennal segment broad basally, broadly articulated with preapical segment => 30

26

  • Lamella on propodeal declivity narrow, broadest dorsally and tapering toward base, its posterior (free) margin straight to shallowly concave => Strumigenys anetes
  • Lamella on propodeal declivity broad, broadest at about its midlength, its posterior (free) margin sdistinctly convex => 31

27

  • With head in profile the ventral surface with a broad concave impression behind the level of the eye; preapical tooth of mandible hook-shaped and arising from the dorsal surface; with head in full-face view the upper scrobe margins suddenly constricted by a deep indentation on each side just in front of the level of the eye => Strumigenys chyzeri
  • With head in profile the ventral surface evenly convex behind the level of the eye; preapical tooth of mandible not hook-shaped, arising from the inner margin; with head in full-face view the upper scrobe margins without a sudden constricted deep indentation on each side just in front of the level of the eye => 32

28

  • Dorsum of mesonotum with 1 pair of stiffly erect simple hairs => 33
  • Dorsum of mesonotum with 3 or more pairs of stiffly erect hairs => 34

29

  • First gastral tergite with abundant long fine simple hairs that are either elongate-filiform or flagellate and are acute apically; mesonotum with 3 pairs of stiffly erect simple blunt hairs => Strumigenys geryon
  • First gastral tergite either hairless or equipped with hairs that are short, stiff and blunt, or remiform to clavate; mesonotum without 3 pairs of stiffly erect simple blunt hairs => 35

30

  • Dorsum of pronotum with a pair of simple or flagellate standing hairs as well as the humeral pair; scape relatively shorter, SI in range of 56-83 => 36
  • Dorsum of pronotum without standing hairs except for the humeral pair; scape relatively longer, SI in range of 87-100 => 37

31

  • Mandible with a minute preapical denticle; pronotal dorsum with a pair of standing hairs as well as the humeral pair => Strumigenys orthanetes
  • Mandible without a trace of preapical dentition; pronotal dorsum without standing hairs except for the humeral pair => 38

32

  • Katepisternum mostly sculptured, with a small smooth patch medially, metapleuron and side of propodeum entirely reticulate-punctate; larger species with longer scapes, HL 0.68-0.72, SL 0.46-0.50, SI 98-102 => Strumigenys ferocior
  • Katepisternum mostly to entirely smooth, metapleuron and side of propodeum partially to entirely smooth; smaller species with shorter scapes, HL 0.52-0.50, SL 0.32-0.38, SI 85-93 => Strumigenys mayri

33

  • Inner margin of mandible with a narrow lamella so that the margin is shallowly convex for part of its length; mandibles and scapes longer, MI 45-48, SI 75-83; in dorsal view basigastral costulae longer than disc of postpetiole => Strumigenys jugis
  • Inner margin of mandible without a lamella, the margin shallowly concave throughout its length; mandibles and scapes shorter, MI 33-37, SI 61-65; in dorsal view basigastral costulae shorter than disc of postpetiole => Strumigenys juxta

34

  • Cephalic dorsum with conspicuous appressed spoon-shaped to scale-like hairs; upper scrobe margin fringed with spoon-shaped hairs; pronotal dorsum without standing hairs except for the short stubbly humeral pair; scape relatively short, SI 57-58 => Strumigenys nummula
  • Cephalic dorsum with inconspicuous narrowly spatulate ground-pilosity; upper scrobe margin fringed with narrowly spatulate hairs; pronotal dorsum with at least one other pair of standing hairs as well as the humeral pair; scape relatively long, SI 68-89 => 39

35

  • Mandibles shorter, MI 26-38, intercalary denticle closest to apicoventral tooth smaller than the one dorsal to it; dorsal surfaces of head, pronotum or both with flat scale-like or orbicular hairs, or with closely applied broadly spoon-shaped hairs => 40
  • Mandibles longer, MI 43-55, intercalary denticle closest to apicoventral tooth larger than the one dorsal to it; dorsal surfaces of head and pronotum without flat scale-like or orbicular hairs, without closely applied broadly spoon-shaped hairs => 41

36

  • Disc of postpetiole unsculptured, smooth and shining => 42

37

  • With head in profile cephalic dorsum with two pairs of erect flagellate hairs, one pair close to highest point of vertex, the other close to the occipital margin; with petiole in profile the ventral curtain laminar rather than densely spongiform => Strumigenys segrex
  • With head in profile cephalic dorsum with one pair of erect flagellate hairs, close to the occipital margin, or without erect flagellate hairs; with petiole in profile the ventral curtain densely spongiform => 43

38

  • Mandibles and scapes relatively long, MI 45-47, SI 88-96, head averaging shorter, HL 0.68-0.77; colour darker, head and mesosoma dark brown to black => Strumigenys paranetes
  • Mandibles and scapes relatively short, MI 38-41, SI 77-83, head averaging longer, HL 0.76-0.91; colour lighter, head and mesosoma medium brown => Strumigenys dysanetes

39

  • Bulla of gland on dorsum of each femur an elongate streak, its maximum length about one quarter the total length of the femur; erect hairs on first gastral tergite long, soft and slender, evenly tapering to acute apices; apicoscrobal hair absent; scape longer, SI about 89 => Strumigenys gryphon
  • Bulla of gland on dorsum of each femur a small oval close to the apex or difficult to discern, its maximum length much less than one quarter the total length of the femur; erect hairs on first gastral tergite stiff and short, stout and not tapering to acute apices; apicoscrobal hair present; scape longer, SI 68-78 => 44

40

  • Leading edge of scape with the median third of its length expanded into a broad, roughly D-shaped lobe, because of this lobe SL only about 1.75 X maximum width of scape; anterior clypeal margin extended laterally, with mandibles fully closed the distance from the anterolateral clypeal angle to the point where the outer margin of the mandible intersects the clypeal margin is about equal to the basal width of mandible => Strumigenys pnyxia
  • Leading edge of scape evenly shallowly convex, the median third of its length not expanded into a broad D-shaped lobe, SL at least 4.0 X maximum width of scape and usually more; anterior clypeal margin not extended laterally, with mandibles fully closed the distance from the anterolateral clypeal angle to the point where the outer margin of the mandible intersects the clypeal margin is much less than the basal width of mandible => 45

41

  • Larger species with shorter mandibles, HL 0.82-0.90, HW 0.64-0.74, MI 40-46 => Strumigenys buleru

42

  • Metapleuron and side of propodeum reticulate-punctate; katepisternum partially to entirely reticulate-punctate; larger species, HW 0.45-0.46, SL 0.36-0.38 => Strumigenys alexetrix
  • Metapleuron, side of propodeum and katepisternum entirely smooth and shining; minute species, HW 0.33-0.38, SL 0.22-0.28 => 46

43

  • Dorsum of propodeum smooth or nearly so, much less densely sculptured than promesonotal dorsum; dorsolateral margin of propodeum on each side with a longitudinal vertical cuticular lamella; mesonotum with a median longitudinal carina that extends its entire length => Strumigenys belua
  • Dorsum of propodeum reticulate-punctate, as densely sculptured as promesonotal dorsum; dorsolateral margin of propodeum without a vertical cuticular lamella on each side; mesonotum without a median longitudinal carina => 47

44

  • Apical form of right mandible with one intercalary article, a small tooth that arises from the dorsal surface of the apicoventral tooth, near its base; in dorsal view disc of postpetiole mostly to entirely unsculptured; leading edge of scape with primary row of curved hairs distinctly spatulate, secondary pilosity on leading edge and dorsum of scape is much shorter and much more slender => Strumigenys perplexa
  • Apical form of right mandible with 3 intercalary articles, a medium tooth flanked both above and below by a minute denticle; in dorsal view disc of postpetiole mostly to entirely sculptured; leading edge of scape with primary row of curved hairs simple to very narrowly spatulate, secondary pilosity on leading edge and dorsum of scape approaches the same size => 48

45

  • Dorsal mesosoma smooth and shining; first gastral tergite without standing hairs; apical fork of mandible with 2 intercalary denticles => Strumigenys undras
  • Dorsal mesosoma reticulate-punctate; first gastral tergite with standing hairs present; apical fork of mandible with 3 intercalary denticles => 49

46

  • Mandibles and scapes longer, MI 43-49, SI 70-76; length of preapical tooth at least equal to basal width of mandible, usually slightly greater; with head in full-face view the upper scrobe margin straight; fully closed mandibles in full-face view slender and convex, narrowing slightly from base ot just proximal of preapical booth => Strumigenys harpyia
  • Mandibles and scapes shorter, MI 38-40, SI 59-60; length of preapical tooth distinctly less than basal width of mandible; with head in full-face view the upper scrobe margin convex; fully closed mandibles in full-face view stout, strongly tapering from base ot just proximal of preapical tooth => Strumigenys lycosa

47

  • Katepisternum entirely reticulate-punctate, metapleuron and side of propodeum mostly to entirely reticulate-punctate; cephalic dorsum without erect fine hairs => Strumigenys tisisyx
  • Katepisternum mostly to entirely smooth, metapleuron and side of propodeum with a smooth patch no mostly unscuptured; cephalic dorsum with a pair of erect fine hairs near midline close to occipital margin => 50

48

  • Katepisternum entirely reticulate-punctate, without a smooth patch; head averaging narrower and scapes longer, CI 68-74, SI 74-84 => Strumigenys cingatrix
  • Katepisternum not entirely reticulate-punctate, at least with a smooth patch, may be entirely smooth; head averaging broader and scapes shorter, CI 74-80, SI 66-74 => Strumigenys deuteras

49

  • Inner margin of mandible with a broad translucent cuticular lamella that at its abruptly truncated apex is almost as wide as the preapical tooth is long, space between apex of lamella and preapical tooth a deep narrow cleft; with head in profile the scrobe behind the level of the eye shallow and almost obsolete, without sharply defined margins => Strumigenys guttulata
  • Inner margin of mandible with a slender translucent cuticular crest that at its widest is only a fraction of the length of the preapical tooth, apex of lamella tapering toward base of preapical tooth, the two not separated by a deep narrow cleft; with head in profile the scrobe behind the level of the eye deep and with sharply defined margins => 51

50

  • Posterior (free) margin of propodeal lamella concave at level of spiracle but below this forming a strongly convex projecting lobe, maximum width of lamella below level of spiracle equal to length of propodeal tooth, greater than maximum width of apical antennomere; reticulate-punctate sculpture reduced or partially affaced on pronotal dorsum, weaker and less regular than on mesonotum => Strumigenys mesedsura
  • Posterior (free) margin of propodeal lamella straight to shallowly concave, not forming a strongly convex projecting lobe below level of spiracle, maximum width of lamella below level of spiracle less than length of propodeal tooth, less than maximum width of apical antennomere; reticulate-punctate sculpture on pronotal dorsum equally strongly and regularly developed as on mesonotum => Strumigenys friedae

51

  • Disc of postpetiole mostly to entirely sculptured; promesontal dorsum with flattened broad hairs that are as large, numerous and conspicuous as those on head; head narrower, CI 70-74 => Strumigenys emdeni
  • Disc of postpetiole mostly to entirely smooth; promesontal dorsum with flattened broad hairs that are smaller, less numerous and less conspicuous than those on head; head broader, CI 78-82 => 52

52

  • Katepisternum and all of metapleuron reticulate-punctate; mesonotum without a pair of erect spatulate hairs; smaller species, HL 0.60-0.64, HW 0.48-0.50 => Strumigenys enanna
  • Katepisternum and all of metapleuron smooth and polished; mesonotum with a pair of short erect spatulate hairs; larger species, HL 0.75, HW 0.60 => Strumigenys semirex

References

  1. Bolton, B. (2000) The ant tribe Dacetini. Memoirs of the American Entomological Institute, 65, 1–1028.