Key to Australian Dolichoderus Species

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The following key to Australian Dolichoderus is modified from Shattuck & Marsden (2013[1]).


1

  • Propodeum with elongate spines => 2
  • Propodeum lacking spines => 13

2

  • Pronotum with elongate spines (doriae group) => 3
  • Pronotum rounded, lacking spines (scabridus group) => 8

3

  • Pronotal spines directed laterally and dorsally => Dolichoderus extensispinus
  • Pronotal spines directed anteriorly and approximately parallel to the longitudinal axis of the body => 4

4

  • Pronotal spines long, in dorsal view a line drawn between their tips lies anterior of the pronotal collar => Dolichoderus dentatus
  • Pronotal spines short, in dorsal view a line drawn between their tips intersects the pronotal collar => 5

5

  • First gastral tergite with abundant short erect hairs => 6
  • First gastral tergite generally lacking erect hairs, but occasionally with a few very short, scattered hairs present => 7

6

  • Legs yellow, strongly contrasting with black body; propodeal spines and sometimes antennae dark red to red-brown, lighter in colour than nearby body regions => Dolichoderus doriae
  • Legs dark brown to black, generally similar in colour to the body or at most slightly lighter in colour than body; tips of propodeal spines and antennae very dark brown to black and similar in colour to nearby body regions => Dolichoderus clarki

7

8

  • In front view, propodeal spines directed upward at angle of greater than 60° to horizontal plane (may be almost vertical), the angle between them approximately 45° => Dolichoderus angusticornis
  • In front viewed, propodeal spines directed upward at angle of 45° or less to horizontal plane, the angle between them at least 90° => 9

9

  • Dorsum of petiolar node angular; when viewed from the front base of propodeal spines narrow, the spines forming a “V” with a narrowly rounded angle between their bases; legs long (Western Australia) => 10
  • Dorsum of petiolar node broad, weakly convex to weakly concave; when viewed from the front, base of propodeal spines broad, the spines forming a “U” with a broad concavity connecting their bases (sometimes this region flat or weakly convex); legs short (South Australia and eastward) => 12

10

  • Legs entirely light red or orange => Dolichoderus ypsilon
  • Femora dark reddish-brown or black, tibiae varying from dark brown to light red => 11

11

12

13

  • Posterior face of propodeum weakly concave, separated from the dorsal face by at most a weakly defined angle; sculpturing on head minimal, either essentially absent or consisting of very fine reticulations (australis group) => 14
  • Posterior face of propodeum strongly concave, separated from the dorsal face by a distinct carina; sculpturing on head consisting of large, shallow to moderately deep fovea (scrobiculatus group) => 18

14

  • Head yellowish-red => 15
  • Head dark reddish-brown to black => 17

15

  • Dorsum of propodeum falling away posteriorly so that the angle is below the level of the metanotal groove => Dolichoderus parvus
  • Dorsum of propodeum evenly convex, the angle at approximately the same level as the metanotal groove => 16

16

17

  • First tergite of gaster with elongate erect hairs but lacking appressed pubescence => Dolichoderus australis
  • First tergite of gaster with both elongate erect hairs and fine, silvery appressed pubescence => Dolichoderus goudiei

18

  • Pubescence on first gastral tergite abundant, the individual hairs overlapping => 19
  • Pubescence on first gastral tergite sparse, the individual hairs generally not overlapping, or hairs absent => 21

19

  • Dorsum of pronotum essentially smooth, the sculpturing at most very fine, the surface shiny; metanotal groove relatively deep (SA, southern WA) => Dolichoderus clusor
  • Dorsum of pronotum heavily sculptured, the surface dull; metanotal groove relatively weekly developed (Fig. 24) (north-eastern NSW, Qld) => 20

20

21

22

  • Dorsum of propodeum elongate (longer than posterior face) and weakly convex, the carina separating dorsal and posterior faces produced as sharp shelf; pale markings present near lower margin of eye => Dolichoderus albamaculus
  • Dorsum of propodeum shorter (at most approximately the same length as the posterior face) and strongly convex, the carina separating dorsal and posterior faces a narrow carina; without pale markings near lower margin of eyes => 23

23

  • Dorsum of propodeum highly arched and often with flat or even weakly concave sections; posterior face of propodeum deeply concave and often nearly semicircular; in dorsal view the pronotum with strongly developed shoulders, the area between the shoulders weakly convex to weakly concave => Dolichoderus reflexus
  • Dorsum of propodeum more weakly and evenly convex, occasionally with a flat or nearly flat section posteriorly; posterior face of propodeum less deeply concave and much less semi-circular; in dorsal view the pronotum with only weakly defined shoulders, the area between the shoulders more strongly convex to flat => 24

24

  • Gaster yellowish red and lighter in colour than mesosoma => Dolichoderus omicron
  • Gaster dark brown to black, darker than mesosoma when mesosoma is lightly coloured (similar to mesosoma in colour when entire body dark brown to black) => 25

25

  • Head and pronotum weakly and superficially areolate, the overall sculpturing pattern indistinct => Dolichoderus canopus
  • Dorsum of head and pronotum with large but shallow and closely spaced foveae, the lateral pronotum distinctly striate, the overall sculpturing pattern very distinct => 26

27

  • Head reddish to reddish-brown and lighter in colour than dark brown to black gaster; mesosoma and gaster with both erect hairs and scattered, appressed pubescence => Dolichoderus nigricornis
  • Head dark brown to black and similar in colour to gaster; mesosoma and gaster with erect hairs but little or no appressed pubescence => Dolichoderus formosus

References

  1. Shattuck, S.O. & Marsden, S. 2013. Australian species of the ant genus Dolichoderus (Hymenoptera: Formicidae). Zootaxa 3716, 101–143 (doi 10.11646/zootaxa.3716.2.1)