Dolichoderus parvus

Dolichoderus parvus occurs in drier regions with mallee, heath and dry sclerophyll habitats, primarily along southern coastal regions. It forages at night on low vegetation and nests under rocks. There is also a single collection from the Sydney area, approximately 800kms east of the next nearest record. These specimens match other D. parvus material and there is little doubt they belong to this species. However, the occurrence of this species in eastern New South Wales is in need of confirmation.

Identification
Colour of head yellowish-red; sculpturing on head minimal, either essentially absent or consisting of very fine reticulations; pronotum and propodeum lacking spines; posterior face of propodeum weakly concave, separated from the dorsal face by at most a weakly defined angle; propodeum falling away posteriorly so that the angle is below the level of the metanotal groove.

Although very similar to Dolichoderus kathae and Dolichoderus rutilus, the shape of the dorsal propodeal surface will distinguish this species from others in the australis group.

Identification Keys including this Taxon

 * Key to Australian Dolichoderus Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  parvus. Dolichoderus (Hypoclinea) parvus Clark, 1930b: 263, fig. 16 (w.) AUSTRALIA. Senior synonym of glauerti: Shattuck & Marsden, 2013: 129.
 * glauerti. Dolichoderus (Hypoclinea) glauerti Wheeler, W.M. 1934d: 147 (w.m.) AUSTRALIA. Junior synonym of parvus: Shattuck & Marsden, 2013: 129.

Worker
Yellowish red, mandibles and antennae testaceous, legs clear yellow, gaster brown.

Shining. Head very finely reticulate. Mandibles smooth. Pronotum microscopically reticulate. Mesonotum reticulate, coarser than on the head. Epinotum and node rugose. Gaster shining, microscopically punctate.

Hair yellow, long and erect, abundant throughout, shorter on the antennae and legs. No pubescence apparent.

Head one-fifth longer than broad, the posterior border feebly, the sides strongly convex. Frontal carinae diverging behind, longer than their distance apart. Clypeus convex above, the anterior border convex, with a distinct excision in front. Eyes large and convex, occupying fully one-fourth of the sides of the head. Scapes extending beyond the occipital border by barely one-fourth of their length; first segment of the funiculus one-third longer than the second, third slightly longer than the second. Mandibles finely denticulate on the masticatory border; terminal border with ten large sharp teeth. Thorax twice as long as broad. Pronotum slightly broader than long, flattened above, convex in front and on the sides. Mesonotum convex above. Epinotum as long as broad, the posterior border convex; in profile strongly convex longitudinally, not overhanging the declivity, the latter concave, barely as long as the dorsum. Node scale-like, four times broader than long, the anterior face straight, the dorsum and posterior face convex. Gaster longer than broad, concave in front below. Legs slender.

Shattuck and Marsden (2013) - Sculpturing on the katepisternum (pleuron of the mesothorax) and propodeum varying from smooth to longitudinally striate. In other respects all available material is similar.

Measurements (n=5). CI 79–84; EI 33–37; EL 0.28–0.30; HL 0.93–1.12; HW 0.76–0.88; ML 1.23–1.57; MTL 0.66–0.86; PronI 64.40–71.18; PronW 0.49–0.62; SI 116–125; SL 0.91–1.07.

Dolichoderus parvus was described from Sea Lake, Victoria while D. glauerti was established based on specimens from Rottnest Island, Western Australia, located approx. 2500km to the west. However, based on currently available material there is little separating these forms. Material from the west does show, on average, slightly more extensive sculpturing on the katepisternum (pleuron of the mesothorax) and propodeum and a larger body size while eastern specimens tend to be smoother and slightly smaller. However, the differences are slight, all forms can be found in all areas and numerous intermediate forms exist, making separation based on these characters highly problematic. Additionally, no other characters could be found suggesting that more than a single variable species is involved. Because of this D. glauerti was treated as a synonym of D. parvus by Shattuck & Marsden (2013).

Male
Wheeler (1934), described as glauerti:

Length 3-3.5 mm.

Head one third broader than long, with evenly rounded postocular region and prominent, widely separated ocelli; eyes large and convex, with emarginate internal orbits; cheeks straight, about one third as long as the eyes, anteriorly converging. Mandibles small, acute, with concave external and straight, minutely denticulate masticatory borders. Clypeus similar to that of the worker but the median emargination smaller; frontal carinae distinct. Antennal scapes stout, a little more than twice as long as broad, first funicular joint slightly longer than broad, second somewhat more than three times as long as broad, remaining joints, except the last gradually decreasing in length. Thorax short and stout, through the wing-insertions as broad as the head; pronotum and anterior end of mesonotum in profile straight and perpendicular, forming nearly a right angle with the somewhat flattened posterior portion of the mesonotum; scutellum prominent; epinotum higher than long, the base convex anteriorly, somewhat sloping and passing into the longer, perpendicular declivity through a rounded angle. Mesonotum from above subhexagonal, as broad as long; scutellum nearly as long as broad. Petiole with a low, thick, sub cuboidal node, which is nearly twice as broad as long and somewhat narrower in front than behind. Gaster rather slender; stipites of genitalia triangular, slightly longer than broad, acuminate; volsellae small, cultrate. Legs slender.

Subopaque; gaster shining; head, thorax, petiole and legs finely and sharply reticulate, the head more coarsely; gaster finely shagreened as in the worker. Scutellum with three small pit-like impressions on each side.

Erect hairs shorter and less numerous than in the worker, absent on the gaster, except at its tip. Pubescence present on appendages and gaster, yellowish, rather long and appressed, but dilute.

Black; incisures of gaster and terminal tarsal joints pale piceous; wings white, with brownish veins and dark brown pterostigma.

References based on Global Ant Biodiversity Informatics

 * Heterick B. E. 2009. A guide to the ants of south-western Australia. Records of the Western Australian Museum Supplement 76: 1-206.
 * Heterick B. E., M. Lythe, and C; Smithyman. 2012. Urbanisation factors impacting on ant (Hymenoptera: Formicidae) biodiversity in the Perth metropolitan area, Western Australia: Two case studies. Urban Ecosyst. DOI 10.1007/s11252-012-0257-19
 * Shattuck S. O., and S. Marsden. 2013. Australian species of the ant genus Dolichoderus (Hymenoptera: Formicidae). Zootaxa 3716(2): 101-143.