Dolichoderus tuberifer

D. tuberifer is a typical herdsmen with all behavioural characteristics of the herdsmen lifestyle. The majority of the population is species-specifically associated with species of the allomyrmococcine genus Malaicoccus. Some populations live without Allomyrmococcini partners, which most probably results from a secondary loss of the specific partners. (Dill 2002)

Identification
Dill (2002) - A member of the Dolichoderus cuspidatus species group. Dolichoderus tuberifer is well defined by its areolate-rugose sculpturing of the head in combination with the shape of the alitrunk, particularly the typical shape of the mesonotum hump. However, many of the characters given in the description vary considerably. As in all other species of the species group, especially colour, body size, and denseness of the pubescence are very variable even within a single nest series. Yet, some geographical trends seem to be significant. For instance, in comparison to the Sumatran populations, the populations from Peninsular Malaysia are characterized by a coarser areolate-rugose sculpturing with deeper, pit-like meshes, and a much deeper and broader median superoccipital pit. These characters are especially weakly developed in certain specimens from West-Sumatra (type series from Mt. Singalang and the series from Sungei Kumbang), while other West-Sumatran material (from Danau Maninjau and Lembah Anai) and a series from North-Sumatra (Si Rambe) occupy an intermediate position. The population from Mt. Singalang (type and non-type series) differs further from all other tuberifer in the presence of short erect hairs on the dorsal face of the gaster. The only other known species of the Dolichoderus cuspidatus group that has a dorsal pilosity is Dolichoderus pilinomas, which in many respects links the cuspidatus group with the pilose Dolichoderus thoracicus group. Another considerably variable character is the shape of the propodeum, particularly the transition between the ascending dorsal face and the declivity (from sharp-edged to rounded), and the development of the tip-like expanded corners. However, these extremes in the development of the mentioned characters are connected by clinal series.

Regarding the shape of the mesonotum, tuberifer is very similar to Dolichoderus maschwitzi and Dolichoderus magnipastor from Sabah. The areolate-rugose sculpturing of the head resembles Dolichoderus modiglianii, in the tuberifer populations with weak development of the character, and magnipastor in those with coarser areolate wrinkles. The tuberifer populations with distinctly expanded corners of the propodeum are close to Dolichoderus erectilobus in this respect.

Distribution
Dill (2002) - Malay Peninsula, West Sumatra and southern part of North Sumatra. Particularly common in mountain forests in altitudes of about 1,000 m a.s.l..

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia. Oriental Region: Thailand.

Nomenclature

 *  tuberifer. Dolichoderus tuberifer Emery, 1887a: 255, pl. 4, fig. 29 (w.) INDONESIA (Sumatra). Dill, 2002: 49 (q.m.). Combination in D. (Hypoclinea): Emery, 1894c: 229. See also: Dill, 2002: 48.

Worker
Dill (2002) - Lectotype in brackets: HL 1.12-1.49 [1.27]; HW 1.08-1.49 [1.25]; EL 0.26-0.33 [0.29]; SL 0.98-1.22 [1.14]; AL 1.50-1.94 [1.63]; PnW 0.71-0.96 [0.78]; ML 0.43-0.63 [0.49]; MW 0.27-0.47 [0.35]; PpL 0.63-0.88 [0.71]; PpW 0.51-0.65 [0.55]; PpH 0.49-0.65; PpSW 0.33-0.53; PtL 0.33-0.47 [0.43]; PtW 0.36-0.49 [0.39]; TL 4.43-6.29 [4.78]. Indices: CI 92-100 [98]; OI 22-25 [23]; SI 82-92 [91]; MI 126-164 [139]; PpSPpI 64-83; (n = 24).

Head: From dark-brown to black, antennae reddish-brown to dark-brown; finely punctate (= micro-imbricate); this fine sculpturing superimposed by a coarser, areolate-rugose “net” of ± circular or oval, pit-like, ± shining meshes (figs. III-62a-c), which are distinct and deep (e. g. Peninsular Malaysia) or indistinct and very shallow (type series); matt, sometimes (e. g. Fraser's Hill series) iridescent. Antennae and entire head (except frontal triangle) finely and densely pubescent, void of erect hairs. Head hardly longer than wide, occipital margin emarginate, usually with a median superoccipital pit (fig. III-62a), which varies from indistinct and very shallow (type series; Sg. Kumbang series) to distinct and deep (Peninsular Malaysia).

Alitrunk: From yellow to yellow-brown, reddish-brown, or black; legs yellow-brown to red-brown. Entire alitrunk, except the smooth and shining declivity of the propodeum, irregulate punctate or reticular (= micro-imbricate), and additionally ± coarsely areolate-rugose (similar to head); pubescent; erect hairs very scarce and restricted to ventral face and coxae. “Shoulder” corners of pronotum indistinct, dorsal face of pronotum ± flat. Mesonotum forming a bluntly coniform hump; its anterior slope, in profile, ascending distinctly steeper than the dorsal face of pronotum (fig. III-13b); its posterior part, in profile, at first a ± distinct flattened kink, distinctly flattened. Posterior margin of ascending dorsal face of propodeum usually ± sharp-edged (but rounded in type series) and medially depressed, sometimes with somewhat expanded lateral corners (not in type series), but not or only very weakly overhanging the backwards sloping concave declivity (fig. III-13b); declivity smooth or very finely reticulate and shining.

Petiolus: From yellow-brown to medium-brown to black; pubescent. Scale entire or weakly emarginate.

Gaster: From yellow-brown to dark-brown or black; basal parts of 1st and 2nd tergite usually lighter. Finely reticulate-punctate (= micro-imbricate); densely, golden-yellowish pubescent; dorsally, particularly on 3rd tergite, pubescense arranged in paired cowlicks, merging in a median line (but ± evenly arranged in type series); very rarely (only type series and other material from type locality), dorsal face of gaster with short erect hairs (about twice as long as hairs of pubescence), which are increasingly dense toward the gaster tip; usually (all other series) erect hairs entirely restricted to ventral face and gaster tip.

Queen
Dill (2002) - HL 1.54-1.63; HW 1.61-1.76; EL 0.30-0.33; SL 1.12-1.20; AL 2.19-2.34; PnW 1.12-1.16; ML 0.88-0.96; ScL 0.37-0.41; MW 0.82-0.91; MH 0.37-0.47; PpL 0.71-0.78; PpW 0.85-0.96; PpH 0.75-0.84; PtW 0.84-0.92; TL 7.14-8.05. Indices: CI 104-110; OI 17-20; SI 68-71; MI 103-112; ScI 28-30; (n = 6).

Coloration and sculpturing similar to workers, except for coarser, areolate-rugose sculpturing less distinct on head; alitrunk, particularly mesopleuron, mesonotum and dorsal face of propodeum less coarsely sculptered than in workers. Entire body, particularly head and scape densely pubescent; pattern of gaster pubescence (cow licks on tergites) similar to that on workers; erect hairs scarce and entirely restricted to ventral face of alitrunk, coxae, as well as sternites and lip of gaster. Occurrence and development of ocelli very variable, ranging from complete absence to the presence of three well developed ocelli, but at least an impression at the position of the anterior ocellus present; median superoccipital pit weaker developed than in workers. Thorax with fused mesonotum (fig. III-67), although its posterior portion (scutellum area) still ± distinctly identifiable; its anterior portion (scutum area) with a median impression, forming a pair of low humps. Dorsal face of propodeum ascending lower than in workers; its posterior corners less distinctly expanded than in workers; its posterior margin rounded, not sharp-edged. Petiole scale much larger and broader than in workers, its upper margin concavely emarginate. Usually distinctly physogastric (length of gaster of material in 75 % alcohol: 3.02-5.09 mm).

Male
Dill (2002) - HL 0.86-0.92; HW 1.07-1.14; EL 0.54-0.57; EW 0.37-0.40; SL 0.33-0.37; CpL 0.25-0.28; MdL 0.35-0.41; AL 1.88-2.03; PnW 1.14-1.27; ML 1.24-1.37; ScW 1.08-1.16; PpW 0.71-0.73; PpH 0.71-0.78; PtW 0.36-0.39; TL 4.78-5.28. Indices: CI 121-125; OI 49-50; OI2 59-63; OI3 34-35; OI4 41-47; SI 30-33 MdI 40-45; MdCpI 138-156; (n = 10).

Typical Dolichoderus males with the typical characters of the cuspidatus group. Coloration and fine sculpturing as in workers, but lacking the coarser areolate-rugose sculpturing; entire body covered by dense, yellowish pubescense. Mandibles long, its masticatory margin distinctly longer than clypeus; eyes very large; median superoccipital pit usually well developed. Strongly vaulted, typical flight-thorax ; scutum wide, ± as wide as head.

Type Material
Syntype workers, Sumatra: Mt. Singalang (O. Beccari) [examined]. One syntype here designated as Lectotype (MCSN).

In several museum collections (e. g., ), the material collected by E. Modigliani in 1890-91 in Si Rambo and described by Emery (1900) is labelled as “type”. Obviously, this material was not subject of Emery’s (1887) first description of tuberifer and thus, has no type status.