Key to Myrmicinae genera of the southwestern Australian Botanical Province

This key to workers 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 1.

1

Distinctive ants with triangular, deeply emarginate heads (e.g. Figures 92, 94, 95); antennal segments (including the scape) less than nine; mandibles usually elongate, sometimes tongs-like . . . . . 2

Figure 92.

Figure 94.

Figure 95.

Ants not as above, heads more rounded (Figure 93); antennal segments nine or more; mandibles triangular . . . . . 6

Figure 93.

2

return to couplet #1

Mandibles long and thin, meeting only at the tips (Figure 94) . . . . . 3

Figure 94.

Mandibles more elongate-triangular in shape, meeting along their entire length (Figure 95) . . . . . 5

Figure 95.

3

return to couplet #2

Antennal scape at rest passing below the eye (Figure 96a); head capsule about as long as wide (Figure 96b); nodes without foam-like material around them . . . . . Epopostruma

Figure 96a.

Figure 96b.

Antennal scape at rest passing above the eye (Figure 97); head capsule much longer than wide (Figure 98); nodes may have foam-like cuticular material attached . . . . . 4

Figure 97.

Figure 98.

4

return to couplet #3

Antenna with five segments, the third segment being longer than the other three segments of the flagellum (Figure 99); PF 5,3; waist segments without foam-like cuticular material attached (SW, one rare species) . . . . . Orectognathus (There is a single species present: Orectognathus clarki)

Figure 99.

Antenna with four or six segments (Figure 100); third segment at most the same length as the other segments; PF 1,1; waist segments often with foam-like material attached . . . . . Strumigenys

Figure 100.

5

return to couplet #2

Lateral margins of both petiole and postpetiole with thin, wing-like flanges (Figure 101) . . . . Colobostruma

Figure 101 and 102.

Wing-like flanges found only on postpetiole (petiole has at most a slight ridge) (Figure 102) . . . . . Mesostruma

6

return to couplet #1

Antenna with nine segments; dorsum of anterior mesosoma flattened and projecting to form a shield, often with regular protruding edges and translucent 'windows' between these edges (Figure 103) . . . . . Meranoplus

Figure 103.

Antenna with 10 or more segments; dorsum of mesosoma never forming a shield as above . . . . . 7

7

return to couplet #6

Postpetiole attached to upper surface of gaster, which is heart-shaped when seen from above; petiole flattened; viewed from above, postpetiole often distinctly bilobed (Figure 104) . . . . . Crematogaster

Figure 104.

Postpetiole attached to the front of the gaster, which is not distinctly heart-shaped; petiole usually with a node, not flattened (Figure 105); postpetiole not bilobed as above . . . . . 8

Figure 105.

8

return to couplet #7

Eyes absent or (rarely) single faceted (Figure 106); antennal club 3-segmented . . . . . Monomorium (in part - also #13, #16 and #18; this key also includes the species Trichomyrmex destructor)

Figure 106.

Eyes usually present, though may be small (Figure 107); if minute or absent (in some specimens of Solenopsis belisarius), then antennal club 2-segmented . . . . . 9

Figure 107.

9

return to couplet #8

Viewed from front, area of clypeus below antennal sockets raised into a sharp ridge (Figure 108a); tip of sting with a triangular or club-like appendage projecting upwards from the shaft (Figure 108b); propodeal angle usually a pair of stout spines, sometimes flanges . . . . . Tetramorium

Figure 108a.

Figure 108b.

Viewed from front, area of clypeus below antennal sockets smooth or a dull ridge (Figure 109); tip of sting usually thin and pointed, occasionally slightly flattened, but without appendage (Figure 110); propodeal angle often absent or with pair of protuberances only . . . . . 10

Figure 109.

Figure 110.

10

return to couplet #9

First and second antennal segments much longer than remaining segments and forming a distinct two-segmented club (Figure 111) . . . . . 11

Figure 111.

Antenna either without a club (Figure 112) or with a club of three or more segments (Figure 113) . . . . . 13

Figure 112.

Figure 113.

11

return to couplet #10

Deep, elongate antennal scrobes present, able to accommodate entire antenna; eyes elongate, with lower sector oblique and narrow (Figure 114) . . . . . Mayriella (There is a single species present: Mayriella occidua)

Figure 114.

Antennal scrobes absent; eyes small and round (Figure 115) or vestigial . . . . . 12

Figure 115.

12

return to couplet #11

Rear face of propodeum rounded, never with teeth, spines or flanges (Figure 116a); midpoint of anterior clypeal margin with a single seta, often surrounded by paired setae (Figure 116b); WA species monomorphic or weakly polymorphic . . . . . Solenopsis

Figure 116a.

Figure 116b.

Rear face of propodeum with spines, teeth or flanges (Figure 117a); clypeus with a pair of setae that straddle the midpoint of the anterior clypeal margin (Figure 117b); strongly dimorphic, major workers with a pair of short horns on the vertex of the head capsule in some Eastern states species (major of SWBP species not known) . . . . . Carebara sp. JDM 440)

Figure 117a.

Figure 117b.

13

return to couplet #10

Antennal segments 10. . . . . Monomorium (in part - also #8, #16 and #18; this key also includes the species Trichomyrmex destructor)

Antennal segments 11 or 12 . . . . . 14

14

return to couplet #13

Antennal segments 11 . . . . . 15

Antennal segments 12 . . . . . 17

15

return to couplet #14

Femora and often tibiae of middle and hind legs greatly swollen; petiole round in crosssection, long and low, usually with a pair of short spines or teeth or acuminate (Figure 118); arboreal ants . . . . . Podomyrma

Figure 118.

Femora and tibiae not or only weakly swollen; petiole short or long with a node, but without processes (e.g. Figure 119); species wholly (e.g. Adlerzia) or predominantly (e.g. Monomorium) terrestrial . . . . . 16

Figure 119.

16

return to couplet #15

Central anterior margin of clypeus with a pair of setae surrounded by other setae (Figures 120a and 120b); major and minor workers (i.e. dimorphic worker caste) (Note: Also look for circular striations on the promesonotum.) . . . . . Adlerzia (There is a single species present: Adlerzia froggatti)

Figure 120a.

Figure 120b.

Central anterior margin of clypeus with single seta, which is surrounded by paired setae (Figure 121); single worker caste only (i.e. monomorphic). . . . . Monomorium (in part - also #8, #13, and #18; this key also includes the species Trichomyrmex destructor)

Figure 121.

17

return to couplet #14

Central anterior margin of clypeus with single seta, which is surrounded by paired setae . . . . . 18

Central anterior margin of clypeus with pair of setae, or with numerous setae or lacking setae . . . . . 19

18

return to couplet #17

Maxillary palp (outer palp) five segmented; clypeus not bicarinate; postpetiole (seen from above) much more massive than petiole (Figure 122) . . . . . Cardiocondyla (There is a single species present: Cardiocondyla nuda)

Figure 122.

Maxillary palp with one or two segments; clypeus often bicarinate with the central clypeal region depressed; viewed from above the postpetiole usually smaller or the same size as the postpetiole (Figure 123). . . . . Monomorium (in part - also #8, #13, and #16; this key also includes the species Trichomyrmex destructor)

Figure 123.

19

return to couplet #17

Antenna with loose, four-segmented club (Figure 124); monomorphic (medium-sized yellow or orange ants that have a which have a distinctive nest formed of a deep, wide tunnel surrounded by a pile of loose dirt.) . . . . . Aphaenogaster

Figure 124.

Antennal club three-segmented (Figure 125); Rogeria is monomorphic, the other genera are dimorphic (Pheidole) or polymorphic (Anisopheidole) . . . . . 20

Figure 125.

20

return to couplet #19

In lateral view promesonotum steeply sloping down to the propodeum; dimorphic (Figure 126) . . . . . Pheidole

Figure 126.

In lateral view all segments of mesosoma more-or-less on the same plane, interrupted only by the shallow metanotal groove; monomorphic or polymorphic (Figure 127) . . . . . 21

Figure 127.

21

return to couplet #20

Eyes minute (four facets wide at widest point) (Figure 128); polymorphic . . . . . Anisopheidole (= Pheidole, there is a single species of Pheidole with this character: Pheidole antipodum)

Figure 128.

Eyes moderate (at least eight facets wide at widest point) (Figure 129); monomorphic . . . . . Austromorium

Figure 129.