Dolichoderus erectilobus

Northern Thai populations had the behavioural and ecological characteristics typical for the herdsmen lifestyle (nesting, transport of trophobionts, etc.). One population (from near Doi Kilun Tan) was found in association with the mealybug Paramyrmococcus chiengraiensis. (Dill 2002)

Identification
Dill (2002) - A member of the Dolichoderus cuspidatus species group. Morphologically, erectilobus is closest to Dolichoderus gibbifer and particularly Dolichoderus laotius. D. erectilobus resembles laotius in regard to its dense and even sculpturing (particularly the absence of coarser wrinkles on the alitrunk), the shape of its mesonotum, and the fact that the dorsolateral corners of the propodeum are distinctly cone- like expanded. But, the propodeum of laotius ascends much steeper and higher than in erectilobus, the cone-like expanded propodeum corners are much larger in laotius, and, in profile, distinctly overhang the declivitous face. Although a tendency to expand the dorsolateral propodeum corners can also be seen in other species, such as Dolichoderus feae, Dolichoderus pastorulus, Dolichoderus tuberifer, and partly in gibbifer, the corners are not as distinctly coniform as in erectilobus or laotius. In addition, the former species differ in their coarser sculpturing, at least of parts of the alitrunk, e. g. rugose wrinkles at the mesopleuron.

Distribution
Dill (2002) - Known from northern Vietnam and northern Thailand.

Distribution based on Regional Taxon Lists
Oriental Region: Thailand, Vietnam.

Nomenclature

 *  erectilobus. Dolichoderus (Hypoclinea) erectilobus Santschi, 1920h: 171, fig. 2 (w.) VIETNAM. Dill, 2002: 40 (q.). [Also described as new by Santschi, 1924c: 111.]

Worker
Dill (2002) - holotype in brackets: HL 1.20-1.47 [1.39]; HW 1.10-1.45 [1.29]; EL 0.27-0.33 [0.31]; SL 1.14-1.37 [1.29]; AL 1.59-1.94 [1.75]; PnW 0.73-0.90 [0.84]; ML 0.47-0.61 [0.51]; MW 0.30-0.39 [0.36]; PpL 0.61-0.88 [0.76]; PpW 0.50-0.65 [0.57]; PpH 0.50-0.65 [0.61]; PpSW 0.33-0.47 [0.37]; PtW 0. 33-0.49 [0.39]; TL 4.78-5.79 [5.38]. Indices: CI 86-100 [93]; OI 21-25 [24]; SI 90- 107 [100]; MI 141-167 [141]; PpSPpI 62-76 [66]; PpHLI 70-82 [79]; (n = 20).

Head: From reddish- to medium- and black. Entire head ± evenly densely punctate (= micro-imbricate; fig. III-59a); matt. Antennae and entire head except the frontal triangle covered by light-grey pubescence, void of erect hairs. Head usually somewhat longer than wide, suboval; occipital margin concavely emarginate. Alitrunk: Reddish-brown (type), blackish-brown, or black. Legs from reddish-, yellow-, or dark-brown (type) to blackish-brown. Entire alitrunk pubescent; erect hairs only on ventral surface and coxae; sculpturing similar to head, i.e. densely and ± evenly punctate to finely reticulate (micro-imbricate); even mesopleuron without coarser wrinkles (fig. III -59b). Declivitous face of propodeum very finely reticulate and hardly shining. Ascending dorsal face of pronotum laterally rounded, without distinct lateral delimitation, pronotum “shoulders” indistinct, Mesonotum, in profile, forming a ± evenly vaulted, flat -topped rounded hump without median depression. Cone- like processes on margin of mesopleuron distinct. Propodeum only moderately ascending; the ascending dorsal face almost at right angle to the declivitous face, that slopes almost straightly and slightly backwards (fig. III-7b); the dorsolateral corners of the propodeum expanded to short cone-like processes which often are somewhat flattened dorsoventrally (figs, III-7c-e); transition from ascending to declivitous face between these expanded corners rounded, not angular,

Petiolus: Densely punctate (= micro-imbricate) and pubescent. Apical margin of scale entire, not concavely emarginate.

Gaster: Blackish-brown (type) to black. Densely and finely reticulate-punctate (= micro-imbricate) with fine, light-greyish pubescence, which is evenly combed, i.e. not forming cowlicks and merging to a median line on the third tergite; erect hairs only on ventral face and gaster tip.

Queen
Dill (2002) - HL 1.43-1.53; HW 1.49-1.55; EL 0.31-0.36; SL 1.22-1.29; AL 2.19-2.37; PnW 1.04-1.10; ML 0.91-1.00; MW 0.78-0.88; MH 0.37-0.43; PpL 0.78-0.88; PpW 0.85-0.93; PpH 0.75-0.82; PpSW 0.47-0.65; PtW 0.71-0.91; TL 6.74-7.30. Indices: CI 101-105; OI 20-24; SI 81-86; MI 113-120; PpSPpI 55-70; (n = 7).

Typical herdsmen queen with all characters mentioned in the description of the Dolichoderus cuspidatus group. Colour and sculpturing as in workers; pubescence, as in workers, evenly combed but denser and stronger. Head about as wide as long, suboval; occipital margin distinctly concavely emarginate; median superoccipital pit shallow but usually present. Presence and development of ocelli very variable. Massive mesonotum, in profile. ± evenly vaulted; often, the former delimitations of the fused scutum and scutellum still recognizable by the shape of the outline. Some specimens with vestigial tegulae or wingbuds (figs. III-70b-c). Propodeum only moderately ascending, its dorsal face almost horizontal, its corners rounded and distinct, but less distinctly coniform than in workers. Petiole scale about as high and wide as propodeum, its apical margin entire or weakly emarginate.

Type Material
Dill (2002) - Holotype (unique syntype) worker, Vietnam: Tonkin: Hanoi (Fouquet) [examined].

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C. 1977. Katalog der Typen von Formicidae (Hymenoptera) der Sammlung des Naturhistorischen Museums Basel (2. Teil). Mitt. Entomol. Ges. Basel (n.s.) 27: 61-102.
 * Ogata K. 2005. Asian ant inventory and international networks. Report on Insect inventory Project in Tropic Asia TAIIV: 145-170.
 * Santschi F. 1920. Fourmis d'Indo-Chine. Annales de la Société Entomologique de Belgique 60: 158-176.
 * Santschi F. 1924. Fourmis d'Indochine. Opuscules de l'Institut Scientifique de l'Indochine 3: 95-117
 * Zryanin V. A. 2011. An eco-faunistic review of ants (Hymenoptera: Formicidae). In: Structure and functions of soil communities of a monsoon tropical forest (Cat Tien National Park, southern Vietnam) / A.V. Tiunov (Editor). – M.: KMK Scientific Press. 2011. 277 р.101-124.