Camponotus consobrinus

A ground nesting species that recruits via tandem running. Alate specimens at SAMA indicate that nuptial flights occurred near Adelaide on 20 January 1991 and 21 January 1992.

Identification
A member of the Camponotus nigriceps species group. McArthur and Adams (1996) - Distinctly polymorphic. Maximum frequency of head widths in minor workers occurs at about 1.75 mm, in medium workers at about 2.8 mm and in major workers at about 3.25 mm. The relationship between log HW and Jog HL is practically linear. Major workers, whose role is to defend the nest, have developed large muscles attached to their mandibles. Thus, major workers possess disproportionately wide heads (Huxley 1936). Some populations of dark coloured C. consobrinus possess suberect pubescence on tibiae.

C. consobrinus, Camponotus loweryi and Camponotus longideclivis always lack setae on the gula and they may be distinguished as follows. C. loweryi major workers (maximum HW = 4·3 mm) are larger than C. consobrinus (maximum HW = 3·6 mm) and C. longideclivis (maximum HW = 3·7 mrn). Gaster colour in C. loweryi shows little variation from posterior to anterior whereas C. consobrinus is distinctly bicoloured. In Mallee areas, C. consobrinus, C. loweryi, Camponotus clarior and Camponotus nigriceps are sympatric. In the Blue Mountains of New South Wales, C. consobrinus and Camponotus pallidiceps are sympatric. In the north-east of New South Wales C. consobrinus and Camponotus eastwoodi are sympatric.

Distribution
McArthur and Adams (1996) - The known distribution is confined to south-eastern and eastern Australia. There is a single pinned specimen of C. consobrinus in ANIC labelled 'Perth. John Clark'. We await other finds before including it in our distribution map of this species.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  consobrinus. Formica consobrina Erichson, 1842: 258 (q.) AUSTRALIA. Smith, F. 1858b: 41 (w.); Imai, Crozier & Taylor, 1977: 346 (k.). Combination in Camponotus: Roger, 1863b: 4; in C. (Tanaemyrmex): Wheeler, W.M. 1933b: 22. Senior synonym of dimidiatus: Wheeler, W.M. 1933b: 23; Clark, 1934c: 70; of obniger: McArthur & Adams, 1996: 22.
 * dimidiatus. Camponotus dimidiatus Roger, 1863b: 4 (w.) AUSTRALIA. Combination in C. (Myrmoturba): Forel, 1913g: 181; in C. (Tanaemyrmex): Emery, 1925b: 103. Junior synonym of nigriceps: Mayr, 1876: 63. Revived from synonymy as subspecies of nigriceps: Emery, 1887a: 211; Stitz, 1911a: 372; Forel, 1915b: 97; Crawley, 1922c: 35. Junior synonym of consobrinus: Wheeler, W.M. 1933b: 23; Clark, 1934c: 70.
 * obniger. Camponotus nigriceps r. obniger Forel, 1902h: 506 (s.w.) AUSTRALIA. Forel, 1910b: 72 (q.). Combination in C. (Tanaemyrmex): Emery, 1925b: 103. Subspecies of consobrinus: Wheeler, W.M. 1933b: 23; Clark, 1934c: 71; of nigriceps: Taylor & Brown, D.R. 1985: 117. Junior synonym of consobrinus: McArthur & Adams, 1996: 22.

Description
Black,shining head dark sides of the thorax and legs ferruginous. Female. Length 6 lines (12.5 mm). Close to C herculaneus. Antennae scape black. Head is just wider than thorax. Black,opaque above, sparingly punctated obsoletely, finely grooved between the median ridges, two carinae between the antennae, carinae slightly bow shaped. Mandibles and palps black. Thorax oblong, somewhat compressed, smooth dorsal part of the notum with scattered punctures. Node subovate, front and back flat, ferruginous. Gaster with sparse and fine punctations, pilosity scarce. Black and shining, forepart is ferruginous. Wings are dark, stigmata and nerves are yellow. Differs from C.herculaneus by the less upright stature, dark head black border, thorax longer, dorsal metathorax black, gaster scarcely punctated, feet completely reddish.

McArthur and Adams (1996) - Colour: head black to red brown; mesosoma, node black to yellow including orange; anterior gaster lighter than posterior, posterior gaster usuall near colour of head. Pilosity always absent on gula; setae erect slightly forward pointing. 0.3-0.5 mm long on mesosoma dorsum, 3-10 on propodeum (Fig. 15 a, b), 5-20 on mesonotum, 15-30 on pronotum, plentiful on gaster pointing backward; on head and mandibles more erect and shorter, not plentiful. Short setae on scapes raised to an inclination of up to 20° when viewed from front. Short setae on midtibiae: inclination 5-40°. Pubescence(= short setae, length always < 0.2 mm) on head and mesosoma adpressed, spacing > setae length. Integument: glossy finely reticulate, front of head with shallow sparse punctation. Node summit viewed from the rear: straight or convex (Fig. 12b), occasionally slightly concave in largest majors.

HW = 1.30-3.30 mm; HL = 1.75-3.40 mm; n = 261. TL = 2.95-3.00 mm; n = 49. TL = 1.9 + 1.87 log HW (n = 49, r = 0.93, s.e.(y). = 0.07, s.e.(x)., = 0.07). PD:D = 1.3 in major workers increasing to 3.0 in minor workers.

Etymology
McArthur and Adams (1996) - Consobrina (Latin: cousin). Erichson (1842) recognised some similarity of this species to Formica herculaneus.