Dolichoderus scabridus

Dolichoderus scabridus is one of the most frequently encountered species within the genus, occurring from north-eastern New South Wales south and west to the Adelaide, South Australia region. It is found in a wide range of forested habitats ranging from mallee and spinifex on sand through dry sclerophyll to wet sclerophyll; they have also been found in pine plantations. Workers forage in columns on the ground, on rotten logs and on tree trunks. Nests occur in rotten branches, logs and stumps on the ground, under bark and in soil under rocks.

The following literature has examined this taxon: Clark (1930) (male description), Wheeler and Wheeler (1951) (larval description), Cavill and Hinterberger (1960a) (glandular compounds), Cavill and Hinterberger (1960b) (glandular compounds), Crozier (1970) (karyotype), Wheeler and Wheeler (1974) (larva); Imai, Crozier and Taylor (1977) (karyotype), Blum and Hermann (1978) (venom and venom apparatus) and Freeland et al. (1982) (behaviour, morphology).

Identification
Pronotum rounded, lacking spines; propodeum with elongate spines directed upward at angle of 45° or less to horizontal plane, the angle between them at least 90°; dorsum of petiolar node broad, base of propodeal spines forming a "U" with a broad concavity connecting their bases (sometimes this region flat or weakly convex); legs yellowish-red in colour, distinctly lighter than the colour of the body.

This species is most similar to Dolichoderus inferus but differs in having yellowish-red legs. This species is also similar to Dolichoderus ypsilon, Dolichoderus rufotibialis and Dolichoderus niger, but in D. scabridus (and D. inferus) the petiolar node is broad rather than angular, and the bases of the propodeal spines form a broad "U" rather than a narrowly angled "V" when viewed from the front.

Key to Australian Dolichoderus Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  scabridus. Dolichoderus scabridus Roger, 1862a: 244 (w.) AUSTRALIA. Clark, 1930b: 257 (m.); Wheeler, G.C. & Wheeler, J. 1951: 176 (l.); Crozier, 1970: 119 (k.). Combination in D. (Hypoclinea): Emery, 1894c: 228; in D. (Diceratoclinea): Wheeler, W.M. 1935c: 69. Senior synonym of foveolatus: Mayr, 1870b: 953; of ruficornis: Shattuck & Marsden, 2013: 134. See also: Shattuck, 1994: 64.
 * foveolatus. Polyrhachis foveolatus Lowne, 1865b: 334 (w.) AUSTRALIA. Junior synonym of scabridus: Mayr, 1870b: 953.
 * ruficornis. Dolichoderus (Hypoclinea) scabridus var. ruficornis Santschi, 1916c: 175 (w.) AUSTRALIA. Clark, 1930b: 258 (m.). Junior synonym of scabridus: Shattuck & Marsden, 2013: 134.

Type Material


Dolichoderus ruficornis was established as a subspecies of D. scabridus. Its type specimens differ from typical D. scabridus in having the antennal scapes red rather than dark reddish-brown. No other differences could be found between these two forms by Shattuck & Marsden (2013) and given the minor overall differences in antennal colour both forms were considered to belong to a single species. It should be noted, however, that the D. ruficornis form predominates at lower elevations in South Australia although it has also been found in Victoria (a single collection from Greensborough) while the D. scabridus form from South Australia is generally found at higher elevation sites in the Flinders Ranges. Across Victoria and New South Wales the D. scabridus form predominates.

Description
All specimens very similar with the exception of the antennal scape colour, which varies from red to dark reddish-brown.

Measurements (n=5). CI 93–100; EI 19–24; EL 0.26–0.33; HL 1.34–1.47; HW 1.26–1.47; ML 1.89–2.10; MTL 1.10–1.22; PronI 68.58–74.77; PronW 0.91–1.04; SI 95–106; SL 1.30–1.46.

Additional References

 * 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).