Camponotus wiederkehri and perjurus species-groups

Among the Australian fauna, Shattuck & McArthur (2002) recognized and revised two species groups, those of wiederkehri and perjurus. What follows are verbatim group definitions and keys from their work:

Definition of the C. wiederkehri species group

Members of the C. wiederkehri species group can be separated from other Australian Camponotus by the presence of a cluster of four or more distinct elongate curved or "J" -shaped hairs on the base of the mentum (near the posterior region of the buccal cavity) in all worker castes (Fig. I). In a few species related to C. ephippium similar hairs are present but these are scattered along the length of the mentum rather than being present as a posterior cluster.

Complexes within the C. wiederkehri species group

The C. wiederkehri species group can be divided into four complexes as follows. While it is likely that these complexes represent monophyletic groups (and there is no evidence that they do not) synapomorphies supporting these groupings have not been sought in this study. It is more appropriate for these studies to be developed as a holistic study of the genus.

1. aurocinctus complex: Includes C. arenatus, aurocinctus, owensae, setosus and versicolor. This complex is defined by the presence of a distinct and angular metanotal groove in minor workers which is depressed (sometimes only slightly) below the anterior region of the propodeum (Figs 3, 8, 9).

2. ceriseipes complex: Includes C. ceriseipes, donnellani, prosseri and rufonigrus. In this complex the posterior section of the mesonotum is weakly but distinctly convex immediately anterior of the metanotal groove (more so in minors, less so in majors) and the metanotal groove in minors varies from a distinct angle to a shallow concavity (Figs 12, 14, 18, 34, 36).

3. postcornutus complex: Includes C. postcornutus. In this complex the entire mesosoma in minor workers is strongly arched, lacks a metanotal groove and the posterior face of the propodeum is only weakly differentiated from the dorsal face (Fig. 31 ); in major workers the posterior comers of the head taper rearv.ards into blunt protuberances (Figs 28, 29).

4. terebrans complex: Includes C. gouldianus, terebrans and wiederkehri. In this complex the posterior section of the mesonotum is flat (or nearly so) immediately anterior of the metanotal groove and the metanotal groove in minor workers is absent or weakly developed (Figs 23, 47, 58).

Definition of the C. perjurus species group

This species group is recognised by having the head produced upwards so that its attachment to the pronotum is well below its upper margin (Fig. 61 ). It has a reduced number of hairs on the mentum compared to species of the wiederkehri group, approaching the arrangement found in relatives of C. ephippium. This group contains a single species, C. perjurus (AntWiki), described below.

Key to workers of the Camponotus wiederkehri species group

1. Erect hairs present on all surfaces of tibiae ...... 2

- Erect hairs absent from outer surfaces of tibiae, inner surface with a double-row (although appressed pubescence may be present) ............ .4

2. Metanotal groove in minor worker a distinct but sometimes shallow trough (Fig. 42); known only from the Kimberley region of northern Western Australia (Fig. 43) .................................... setosus

-Metanotal groove in minor worker weakly developed (Fig. 23) or absent (Fig. 47); known only from southern Australia (Figs 24, 48) ....... 3

3. Number of erect hairs on propodeum greater than 40; pubescence on head and gaster abundant and with individual hairs overlapping; summit of petiolar node in profile rounded in minor workers (Fig. 23), a blunt angle in major workers (Fig. 21) .......................... . ......... gouldianus

- Number of erect hairs on propodeum less than 25; pubescence on head and gaster sparse and with individual hairs generally non-overlapping or at most only slightly overlapping; summit of petiolar node in profile angular in both minor and major workers (Figs 45, 47) ................. terebrans

4. Entire mesosoma in lateral view strongly arched, lacking a metanotal groove and with the posterior face of the propodeum only weakly differentiated from the dorsal face (Figs 29, 31); posterior corners of head of major worker tapering rearward into blunt protuberances (Figs 28, 29) ............................................. postcornutus

- Mesosoma in lateral view flat or at most with the pronotum and mesonotum weakly arched and separated from the propodeum by a weak angle (Fig. 14) or a distinct, angular or concave metanotal groove (Fig. 9), the posterior face of the propodeum always separated from the dorsal face by a rounded angle (Fig. 14); posterolateral comers of head rounded in majors (Figs 33, 34)............................................................................ 5

5. Metanotal groove in minors depressed below the anterior region of propodeum (Figs 8, 9); metanotal groove in majors angular (Fig. 6); dorsum of petiolar node in minors broadly or weakly convex, flat or weakly concave, the anterior face much shorter than the posterior face (Figs 8, 9); petiolar node in majors broadly rounded above (Fig. 6) ............. 6

- Metanotal groove in minors absent (Fig. 58) or angular (Fig. 14) and always even with the anterior region of propodeum; metanotal groove in majors a broad, shallow angle (Fig. 12); dorsum of petiolar node in minors angular or broadly rounded, the anterior face at most only slightly shorter than the posterior face (Fig. 14); petiolar node in majors angular above (Fig. 12) ........................................................................... 9

6. Dorsal and anterior regions of pronotum dark red-black, distinctly darker than the yellow-red mesonotum and propodeum ................ .. arenatus

- Entire mesosoma uniform in colour, varying from dark red-black to black ............................. 7

7. Elongate ( overlapping) and dense pubescence present on dorsum of head, mesosoma, gaster and tibiae ................................................ owensae

- Short (non-overlapping) and scattered pubescence present on dorsum of head, mesosoma, gaster and tibiae ........................................................... 8

8. Anterior region of first gastral tergite dark reddish black or black, similar in colour to propodeum; metanotal groove in minors distinct and depressed well below the anterior region of propodeum (Figs 8, 9) ...................... aurocinctus

- First and second gastral tergites red, distinctly lighter in colour than the reddish black propodeum; metanotal groove in minors weakly to moderately depressed below the anterior region of the propodeum (Figs 52, 53) .......... versicolor

9. Posterior section of mesonotum flat ( or nearly so) immediately anterior of metanotal groove; metanotal groove absent or weakly developed in minors (Fig. 58); anterior clypeal margin in majors projecting with a straight central region separated from lateral regions by distinct angles (Fig. 55) ............................................ wiederkehri

- Posterior section of mesonotum weakly but distinctly convex immediately anterior of metanotal groove (more so in minors, less so in majors); metanotal groove varying from a distinct angle to a shallow concavity in minors (Figs 14, I 8, 36); anterior clypeal margin in majors broadly convex across entire width (Fig. 11) ........................................................ 10

10. Propodeum with at most 4 elongate erect hairs which are limited to the angle between the dorsal and posterior faces.. . .... donnellani

- Propodeum generally with more than IO erect hairs which are always scattered along the entire dorsal surface............... . .............. 11

11. Metanotal groove well defined and angular (Fig. 39); black head contrasting with red mesonotum .. rufonign1s

-Metanotal groove a weakly defined concavity (Figs 14, 36); head same colour as mesonotum (both either red or black) ................................. 12

12. Scapes relatively short (in minors, SI < 1.5) (Fig. 15); petiolar node of minors generally more upright and narrower (Fig. 14) ............ ceriseipes

- Scapes relatively long (in minors, Sl > 1.4) (Fig. 15); petiolar node of minors generally lower and broader (Fig. 36)....... . ......... prosseri

References

• Shattuck, S. O.; McArthur, A. J. 2002. A taxonomic revision of the Camponotus wiederkehri and perjurus species-groups (Hymenoptera: Formicidae). Trans. R. Soc. S. Aust. 126: 63-90.