Key to Stigmacros of the southwestern Australian Botanical Province

AntWiki: The Ants --- Online
Jump to navigation Jump to search

This worker key is based on: Heterick, B. E. 2009a. A guide to the ants of South-western Australia. Records of the Western Australian Museum, Supplement 76: 1-206. Part 2.

The key produced by McAreavey (1957) is, unfortunately, not easy to use, and may not reflect the outcome of a modern revision of the group; hence it has not been followed here.

You may also be interested in

1

  • Dorsum of node with pair of spines directed posteriad (Figure 408) . . . . . 2
Figure 408.
  • Dorsum of node unarmed, or nearly so (may be divided into pair of blunt lobes or vestigial denticles) (Figure 409) . . . . . 6
Figure 409.

2

return to couplet #1

  • Propodeum armed with two pairs of stout spines; one pair at propodeal angles and one pair directly above propodeal spiracles, respectively (sub-genus Hagiostigmacros) (possibly two species represented here) (Figure 410) . . . . . Stigmacros spinosa
Figure 410.
Stigmacros spinosa antweb1008354 p 1 high.jpg
Stigmacros spinosa antweb1008354 d 1 high.jpg
  • Propodeum armed with one pair of spines or denticles directly above propodeal spiracles, propodeal angles produced as weak or vestigial denticles (Figure 411) . . . . . 3
Figure 411.

3

return to couplet #2

Stigmacros brachytera antweb1008329 p 1 high.jpg
Stigmacros brachytera antweb1008329 d 1 high.jpg

4

return to couplet #3

  • Process directly above propodeal spiracle a short denticle (Figure 412) . . . . . Stigmacros sp. JDM 832
Figure 412.
  • Process directly above propodeal spiracle a stout spine (Figure 413) . . . . . 5
Figure 413.

5

return to couplet #4

  • Yellow species; mesosoma and gaster with many erect setae, gaster also pubescent . . . . . Stigmacros sp. JDM 831
  • Gaster and head brown, mesosoma and appendages light reddish brown; sparse erect setae present only on margins of gastral tergites and underside of gaster, gaster not pubescent . . . . . Stigmacros sp. JDM 622

6

return to couplet #1

  • Gaster moderately to densely pubescent; cuticle of mesosoma microreticulate and usually matt, with many short, erect setae . . . . . 7
  • Gaster, at most, with weak pubescence with appressed setulae normally sparse; cuticle of mesosoma often smooth, shining, rarely with erect setae (if present, these are normally long) . . . . . 9

7

return to couplet #6

  • Black or dark brown species with orange or brownish appendages, petiolar node orange to black . . . . . Stigmacros sp. JDM 341

8

return to couplet #7

  • Propodeum with distinctly longitudinal impressed furrow; propodeal angles blunt (Figure 414); sculpture of head and mesosoma superficial, cuticle more-or-less shiny; pubescence on first gastral tergite dense . . . . . Stigmacros sp. JDM 396
Figure 414.
  • Propodeum without longitudinal furrow or furrow vestigial and barely discernible; propodeal angles denticulate (Figure 415); cuticle of head and mesosoma finely microreticulate; dull; shagreenate; pubescence on first gastral tergite moderate, with short, appressed setae visibly separate . . . . . Stigmacros sp. JDM 829
Figure 415.

9

return to couplet #6

  • Erect setae present on mesosoma; non-marginal, erect setae present on gastral tergites . . . . . 10
  • Erect setae absent from mesosoma; if erect setae present on gaster, then confined to margins of tergites . . . . . 13

10

return to couplet #9

  • Propodeum smoothly rounded without longitudinal furrow or lateral carinae (Figure 416) . . . . . Stigmacros sp. JDM 1046
Figure 416.
  • Propodeum laterally carinate, longitudinal furrow present or absent (Figure 417) . . . . . 11
Figure 417.

11

return to couplet #10

  • In profile, mesonotum convex, its dorsum smoothly rounded into its lateral surfaces (Figure 418) . . . . . Stigmacros inermis
Figure 418.
Stigmacros inermis antweb1008342 p 1 high.jpg
Stigmacros inermis antweb1008342 d 1 high.jpg
  • In profile, mesonotum flat, its dorsal and lateral surfaces distinct, often separated by a strong carina extending fully or partly along the length of the mesonotum (Figure 419) . . . . . 12
Figure 419.

12

return to couplet #11

  • In profile, dorsum of propodeum smoothly confluent with declivitous face; propodeal angle absent (Figure 420); erect setae present on all surfaces of mesosoma . . . . . Stigmacros pilosella
Figure 420.
Stigmacros pilosella casent0281495 h 1 high.jpg
Stigmacros pilosella casent0281495 p 1 high.jpg
  • In profile, dorsal and declivitous faces of propodeum distinct; propodeal angle present (Figure 421); erect setae virtually confined to pronotum (one or two short setae may be evident on mesonotum) . . . . . Stigmacros stanleyi
Figure 421.
Stigmacros stanleyi antweb1008355 p 1 high.jpg
Stigmacros stanleyi antweb1008355 d 1 high.jpg

13

return to couplet #9

  • In profile, pronotum and mesonotum flat and on same plane, or mesonotum weakly convex; mesonotum and often pronotum laterally carinate (Figure 422); ants bicoloured, head, mesosoma and gaster always black or shades of dark red-and-brown, appendages usually much lighter coloured, often yellow or orange. . . . . . 14
Figure 422.
  • In profile, pronotum and mesonotum weakly to strongly convex; pronotum never carinate, dorsum of mesonotum usually smoothly rounded onto sides (Figure 423), occasionally with weak angle between dorsal and lateral surfaces; species concolorous light yellow or orange or shades of brown without strong contrast between body and appendages . . . . . 19
Figure 423.

14

return to couplet #13

  • In dorsal view, head distinctly darker than mesosoma . . . . . 15
  • In dorsal view, head same colour as, or slightly lighter than mesosoma . . . . . 16

15

return to couplet #14

  • Propodeum with flat dorsal and declivitous faces, in profile, propodeal angle strong (Figure 424) . . . . . Stigmacros aemula
Figure 424.
Stigmacros aemula casent0217812 h 1 high.jpg
Stigmacros aemula casent0217812 p 1 high.jpg
Stigmacros aemula casent0217812 d 1 high.jpg
  • Propodeum with a short dorsal face merging imperceptibly into a long, smooth, slightly concave declivitous face (Figure 425); in profile propodeal angle very weak . . . . . Stigmacros epinotalis
Figure 425.
Stigmacros epinotalis antweb1008334 p 1 high.jpg
Stigmacros epinotalis antweb1008334 d 1 high.jpg

16

return to couplet #14

  • In dorsal view, mesonotum with strong punctate-microreticulate sculpture, appearance dull . . . . . Stigmacros anthracina
Stigmacros anthracina antweb1008327 p 1 high.jpg
Stigmacros anthracina antweb1008327 d 1 high.jpg
  • In dorsal view, mesonotum with very fine microreticulation or sculpture lacking, appearance shining . . . . . 17

17

return to couplet #16

  • In profile, propodeum narrow, about 1/2 as wide as high, longitudinal furrow absent, propodeum with oblique outline (Figure 426); fine, microreticulate sculpture present on mesonotum . . . . . Stigmacros sp. JDM 1045
Figure 426.
  • In profile, propodeum about as wide as high; longitudinal furrow present, propodeum with outline of anterior lateral carinae rectangular or describing an arc in a horizontal plane (Figures 427, 428); mesonotal sculpture absent. . . . . . 18
Figure 427.
Figure 428.

18

return to couplet #17

  • Eye large, its width ≥ width of fore tibia; in full-face view (Figure 429a); dorsum of node bilobate (Figure 429b) . . . . . Stigmacros elegans
Figure 429a.
Figure 429b.
Stigmacros elegans casent0172181 head 1.jpg
Stigmacros elegans casent0172181 profile 1.jpg
  • Eye smaller, its width < width of fore tibia (Figure 430a); in full-face view, dorsum of node straight or slightly concave, meeting the sides at an angle (Figure 430b) . . . . . Stigmacros brachytera (most workers)
Figure 430a.
Figure 430b.
Stigmacros brachytera antweb1008329 p 1 high.jpg
Stigmacros brachytera antweb1008329 d 1 high.jpg

19

return to couplet #13

  • Head, mesosoma, node, gaster, most of femora and extreme end of antenna chocolate, tips of femora, tibiae, tarsi and most of antenna ochraceous . . . . . Stigmacros reticulata
Stigmacros reticulata casent0903231 h 1 high.jpg
Stigmacros reticulata casent0903231 p 1 high.jpg

20

return to couplet #19

  • Mesonotum smooth and shining; in profile, weakly convex (Figure 431); head and mesosoma nearly always concolorous yellow or light orange . . . . . 21
Figure 431.
  • Mesonotum with distinct, though sometimes weak sculpture; in profile strongly convex (Figure 432); colour yellowish or brown, head often darker than mesosoma (S. occidentalis complex) . . . . . 24
Figure 432.

21

return to couplet #20

  • In profile, dorsum of propodeum rounded before it meets denticles directly above the spiracles (Figure 433) . . . . . Stigmacros sp. JDM 1050
Figure 433.
  • In profile, dorsum of propodeum angular or rectangular (S. pusilla complex) (Figure 434) . . . . . 22
Figure 434.

22

return to couplet #21

  • In profile, propodeal angles denticulate, directed upward (Figure 435); larger (HW > 0.5 mm) . . . . . Stigmacros pusilla
Figure 435.
Stigmacros pusilla antweb1008349 d 1 high.jpg
  • In profile, propodeal angles not denticulate, directed laterally (Figure 436); smaller (HW < 0.5 mm) . . . . . 23
Figure 436.

23

return to couplet #22

  • Eye moderate (eye width ≈ 0.25 × width of side of head capsule) . . . . . Stigmacros sp. JDM 115
  • Eye large (eye width < 1/3 × width of side of head capsule) . . . . . Stigmacros sp. JDM 188

24

return to couplet #20

  • Pale yellowish species, head concolorous with mesosoma or only slightly darker . . . . . 25
  • Brownish species, head usually distinctly darker than mesosoma . . . . . 28

25

return to couplet #24

  • Node deeply bilobate, lateral processes distinct denticles . . . . . Stigmacros sp. JDM 1067
  • Node not deeply bilobate, lateral processes vestigial or absent . . . . . 26

26

return to couplet #25

  • Eye width moderate (eye width, at most, only fractionally greater than greatest width of scape) . . . . . Stigmacros flava
Stigmacros flava antweb1008337 p 1 high.jpg
Stigmacros flava antweb1008337 d 1 high.jpg
  • Eye large (eye width ≥ 3 x greatest width of scape) . . . . . 27

27

return to couplet #26

  • In dorsal view, mesonotum as long as wide; (Figure 437) . . . . . Stigmacros sp. JDM 1135
Figure 437.
  • In dorsal view, mesonotum 1.5 – 2 x as long as wide (Figure 438) . . . . . Stigmacros sp. JDM 443
Figure 438.

28

return to couplet #24

Stigmacros termitoxena antweb1008719 h 1 high.jpg
Stigmacros termitoxena antweb1008719 p 1 high.jpg
  • Eye smaller, ≈ as wide as antennal scape at its widest point . . . . . 29

29

return to couplet #28

Figure 439.
Stigmacros occidentalis casent0906280 h 1 high.jpg
Stigmacros occidentalis casent0906280 p 1 high.jpg
Figure 440.
Stigmacros glauerti antweb1008339 p 1 high.jpg
Stigmacros glauerti antweb1008339 d 1 high.jpg