Camponotus wiederkehri

This is one of the most commonly encountered and widespread species in the C. wiederkehri group. In southern Australia nests are generally mounds approximately 150 to 200mm in diameter with steeply sloping sides and a flat summit with the entrance in a slight depression in the centre. These mounds are often decorated with small stones. Nests are often in heavy soil in open areas and are less common or are absent from areas of high rainfall. Often several mounds may be seen within a few metres of each other.

Identification
Anterior clypeal margin in major workers projecting, the central region straight with rectangular sides joining the lateral regions. Posterior section of mesonotum flat (or nearly so) immediately anterior of the metanotal groove, metanotal groove essentially absent or weakly developed in minors, a broad, shallow angle in majors. Petiolar node angular or broadly rounded above, the anterior face at most only slightly shorter than the posterior face. Tibiae and scapes lacking erect hairs.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 * . Camponotus weiderkehri Forel, 1894e: 232 (s.w.) AUSTRALIA (Queensland).
 * Combination in C. (Myrmosphincta): Forel, 1912i: 92;
 * combination in C. (Myrmophyma): Forel, 1914a: 269;
 * combination in C. (Tanaemyrmex): Emery, 1925b: 102.
 * Status as species: Emery, 1896d: 373 (in list); Forel, 1902h: 494; Emery, 1925b: 102; Taylor & Brown, 1985: 121; Taylor, 1987a: 16; Bolton, 1995b: 130; Shattuck & McArthur, 2002: 85 (redescription); McArthur, 2007a: 312; Heterick, 2009: 62; McArthur, 2010: 54; McArthur, 2014: 78.
 * Senior synonym of denticulatus: Shattuck & McArthur, 2002: 85; McArthur, 2007a: 295; McArthur, 2010: 54.
 * Senior synonym of latrunculus: Shattuck & McArthur, 2002: 85; McArthur, 2007a: 295; McArthur, 2010: 54.
 * Senior synonym of lucidior: Shattuck & McArthur, 2002: 85; McArthur, 2007a: 295; McArthur, 2010: 54.
 * denticulatus. Camponotus denticulatus Kirby, W.F. 1896: 204 (s.w.) AUSTRALIA (Northern Territory).
 * Combination in C. (Tanaemyrmex): Clark, 1930c: 19.
 * Status as species: Clark, 1930c: 19 (redescription); Taylor & Brown, 1985: 112; Taylor, 1987a: 12; Bolton, 1995b: 96.
 * Junior synonym of wiederkehri: Shattuck & McArthur, 2003: 85; McArthur, 2007a: 295; McArthur, 2010: 54.
 * lautus. Formica lauta Say, 1836: 286 (q.m.) U.S.A. (Indiana).
 * Combination in Camponotus: Emery, in Dalla Torre, 1893: 238.
 * Status as species: Smith, F. 1858b: 54; Mayr, 1863: 417; Cresson, 1887: 256; Dalla Torre, 1893: 238; Emery, 1896d: 378 (in list); Emery, 1925b: 171.
 * Unidentifiable taxon, incertae sedis in Formicinae: Smith, M.R. 1958c: 161; Smith, D.R. 1979: 1467;
 * unidentifiable taxon, incertae sedis in Camponotus: Smith, M.R. 1951a: 847; Bolton, 1995b: 108.
 * lucidior. Camponotus wiederkehri var. lucidior Forel, 1910b: 81 (s.w.m.) AUSTRALIA (Northern Territory).
 * [Misspelled as lucidor by McArthur, 2010: 54.]
 * Crawley, 1915a: 136 (q.).
 * Combination in C. (Tanaemyrmex): Emery, 1925b: 102.
 * Subspecies of wiederkehri: Forel, 1915b: 100; Crawley, 1915a: 136; Emery, 1925b: 102; Taylor & Brown, 1985: 122; Taylor, 1987a: 16; Bolton, 1995b: 109.
 * Junior synonym of wiederkehri: Shatuck & McArthur, 2002: 85; McArthur, 2007a: 295; McArthur, 2010: 54.

Major worker
Medial section of anterior clypeus strongly projecting, its margin straight and lateral comers broadly angular, carina weak. Pronotum and mesonotum a slightly raised even convexity; metanotum with two distinct groves, the anterior section of the propodeal dorsum feebly concave anteriorly and feebly convex posteriorly, propodeal angle widely rounded, posterior face mostly straight, ratio of dorsum to declivity about 1. Anterior and posterior faces of petiolar node straight; summit flat, narrow and sharp, sometimes bidentate, its posterior margin feebly concave. Dorsum and underside of head, mesosoma, petiole, coxa and gaster with plentiful scattered erect setae, reduced numbers on propodeal angle and declivity, absent from scapes, flat lying on tibiae. Head yellow-red to dark brown, antennae red to red-brown, mesosoma and node yellow-red to brown; gaster darker, legs lighter.

Minor worker
Medial section of anterior clypeus strongly projecting, its margin convex, crenulate; carina distinct. Pronotum weakly convex, anterior section of mesonotum weakly convex, the remainder joins with propodeal dorsum to form a long flat surface ending in a widely rounded propodeal angle and short posterior face, ratio of dorsum to declivity about 3. Anterior face of petiolar node mostly convex, summit sharp (in front view pointed), posterior face mostly flat. Dorsum and underside of head, mesosoma, petiole, coxa and gaster with scattered long setae; reduced numbers on propodeal angle and declivity; absent from tibiae and scapes. Entire body clothed with fine pubescence. Mesosoma yellow-red to dark red-brown, sometimes with darker or lighter patches; head, node and gaster generally darker, legs lighter.

Measurements
Workers (n=20). CI 0.80 (minors)— 1.08 (majors); HL 1.51 mm — 3.33mm; I-1W 1.21mm — 3.61mm; ML 2.51mm — 3.83mm; MTL 1.92mm — 2.62mm; PnW 0.97mm — 2.13mm; SI 0.68 (majors) — 1.60 (minors); SL 1.94mm — 2.45mm.

Intraspecific variation
Morphologically, this species (as conceived by Shattuck & McArthur, 2002) shows minimal variation in body shape and pilosity (other than that expected for a polymorphic taxon) but does show considerable variation in colour. The colour ranges from clear yellow-red to black with essentially all grades of colour in between. In most cases the colour is uniform within an individual but various degrees of infuscation on the mesosoma are common. Also, most variation occurs between rather than within nest series although the development of infuscation does vary within nest series. Finally, this colour variation shows little geographic pattern with essentially all colour forms being found in all regions, the only exception being northern regions of the Northern Territory where light forms predominate.

Synonyms
The types of C. wiederkehri and C. wiederkehri lucidior represent the more lightly coloured forms of this taxon. These two taxa were separated based on trivial and non-significant differences in size, sculpturing and the shape of the anterior clypeal margin (Forel 1910) and they clearly represent the same taxon. Camponotus latrunculus represents an intermediately coloured form and compares well with the types of C. wiederkehri. Wheeler (1915) was apparently unaware of C. wiederkehri as he made no mention of it in his description of C. latrunculus and this is likely the cause of this synonymy. The final previously proposed name, C. denticulatus, represents the dark form of this taxon. However, it is morphologically very similar to the other forms placed here and no justification could be found for treating it as a separate taxon.

Worker major. Length 10.5-12 mm. Mandibles slightly convex, armed with 6 or 7 teeth, sub glossy, very finely shagreen, with sparse points and a few striations at the front. Clypeus sub keeled, a medial trapezoidal lobe at the front. Eyes flat. Frontal ridges sinuous hardly diverging at all. Head very large, strongly convex, excavated behind, wider than long (without mandibles). Thorax weakly but distinctly indented between the intermediate segment and the metanotum (scarcely like this in C foreli Emery) Sutures distinct. Intermediate segment a little wider than long. Metanotum (= propodeum) strongly rounded; its two faces of the same length. Node high, very sharp, almost accuminate at the summit. Gaster short and wide. Overall this insect is thick set and stocky. The scapes exceed the occiput. Tibias are sub cylindrical (sub depressed), with a range of little spines quite sparse. Front of the head is sub opaque, densely reticulate. Rest of the body is quite glossy, more weakly shagreen, with sparse fine punctation, faded on the thorax, stronger on the front of the head. A fine yellowish pubescence, quite abundant, forms a duvet over the whole body, limbs and antennae but not on the occiput. Yellowish erect pilosity, very sparse, none on tibias and scapes. Of a red a little dull or brownish, gaster and teeth of the mandibles black, femurs and gastric segments yellowish. Worker minor. Length 6.5 to 7.5 mm. Much like the worker major but rather slender. Head rectangular, a little longer than wide, posterior border straight. Eyes strongly convex, situated towards the posterior 1/4 of the head. The scapes exceed the occiput by more than 1/2 their length. Thorax narrow, elongated, very weakly convex, with a wide feeble indentation, sometimes scarcely visible between the mesonotum and metanotum. The latter is elongated, slightly narrowing, with the declivity very short. Node very thick, rounded at the summit, slightly inclined at the front. Sculpture of the front of the head like the rest. Occiput is pubescent like the rest of the body. Of a dull brownish red, limbs, vertex, dorsum of thorax especially the pedicel more or less brownish. Mandibles reddish or brownish yellow. Punctation sparse and faded everywhere. Otherwise like the worker major but a little more pubescent. Charters Towers Queensland. (M Wiederkehr) Close relative of cinereus and suffusus.

Camponotus weiderkehri lucidor Forel,A. (1910). Worker. Length 7.5 to 14 mm. Much larger than the species type.

Worker major. Differs from the species type by the glossy body, the feeble sculpture, the lobe of the clypeus is sub bidentate, mandibles much longer, armed with 6 or 7 teeth.

References based on Global Ant Biodiversity Informatics

 * Forel A. 1910. Formicides australiens reçus de MM. Froggatt et Rowland Turner. Rev. Suisse Zool. 18: 1-94
 * Heterick B. E., B. Durrant, and N. R. Gunawardene. 2010. The ant fauna of the Pilbara Bioregion, Western Australia. Records of the Western Australian Museum, Supplement 78: 157-167.
 * McArthur A. 2010. A guide to Camponotus ants of South Australia. Adelaide: South Australian Museum, IV + 121 pp.
 * Shattuck S. O., A . J. McArthur. 2002. A taxonomic revision of the Camponotus wiederkehri and perjurus species-groups (Hymenoptera: Formicidae). Transactions of the Royal Society of South Australia 126: 63-90.
 * Taylor R. W. 1987. A checklist of the ants of Australia, New Caledonia and New Zealand (Hymenoptera: Formicidae). CSIRO (Commonwealth Scientific and Industrial Research Organization) Division of Entomology Report 41: 1-92.
 * Taylor R. W., and D. R. Brown. 1985. Formicoidea. Zoological Catalogue of Australia 2: 1-149.