Dolichoderus scrobiculatus

Dolichoderus scrobiculatus is the only species of the genus common in the Australian wet tropics, being found from Cape York Peninsula south to north-eastern New South Wales. It occurs in savannah woodlands to rainforests and nests in tussocks and under rocks. Workers commonly forage on low vegetation.

Identification
Pronotum and propodeum lacking spines; 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; pubescence on first gastral tergite abundant, the individual hairs overlapping; dorsum of pronotum heavily sculptured, the surface dull; gaster similar in colour to body (both dark brown to black).

This species resembles Dolichoderus clusor and Dolichoderus turneri. It can be distinguished from D. clusor by the presence of heavy sculpturing on the pronotum and from D. turneri by the similarly coloured gaster and body (both being dark brown to black in D. scrobiculatus while in D. turneri the gaster is lighter in colour than the body).

Identification Keys including this Taxon

 * Key to Australian Dolichoderus Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

The two southern outlier records, from southern New South Wales and Victoria, were made many years ago and now collections have been made since. The status of this species in these areas seems doubtful.

Nomenclature

 *  scrobiculatus. Hypoclinea scrobiculata Mayr, 1876: 80 (w.) AUSTRALIA. Combination in Dolichoderus: Dalla Torre, 1893: 161; in D. (Hypoclinea): Emery, 1894c: 228. See also: Clark, 1930b: 260.

Worker
Clark (1930) - Black, the thorax sometimes brownish black, mandibles and scapes red, funiculus and legs darker.

Shining. Head, thorax and node coarsely punctate. Clypeus more striate-rugose. Mandibles smooth, with some large shallow punctures. Gaster microscopically punctate.

Hair yellow, erect, long and abundant throughout, shorter on the antennae and legs. Pubescence apparent only on the gaster, where it forms a thin yellowish covering, not hiding the sculpture.

Head longer than broad, the occipital border feebly, and the sides strongly, convex. Frontal carinae dilated at the middle, as long as their distance apart. Clypeus convex above, the anterior border convex, with a deep and wide excision in the middle. Eyes globular, placed slightly behind the middle of the sides. Scapes extending beyond the occipital border by one-fourth of their length; first segment of the funiculus one third longer than the second and third. The masticatory border of the mandibles finely denticulate, the terminal border with ten or twelve sharp teeth. Thorax one and a half times longer than broad. Pronotum almost three times broader than long, feebly convex above. Mesonotum convex above. Epinotum as long as broad, the sides and posterior border feebly convex; in profile the dorsum strongly convex longitudinally, much higher in front than behind, overhanging the declivity, the latter slightly longer than the dorsum and strongly concave. Node barely twice as broad as long, the anterior face feebly, the posterior face strongly, convex; in profile parallel to near the top, where both faces are convex, meeting and forming a ridge on the dorsum. Gaster concave in front below. Legs robust.

Shattuck and Marsden (2013) - All known specimens closely resemble each other.

Measurements (n=5). CI 94–96; EI 26–28; EL 0.26–0.29; HL 1.04–1.12; HW 0.98–1.07; ML 1.39–1.51; MTL 0.79–0.85; PronI 74.95–80.10; PronW 0.76–0.84; SI 96–100; SL 0.94–1.03.