Dolichoderus laotius

Dolichoderus laotius is a herdsmen species. A series from Thailand was associated with the allomyrmococcine mealybug Thaimyrmococcus daviesi. One worker of the alcohol material still held a mealybug in the mandibles. (Dill 2002)

Identification
Dill (2002) - A member of the Dolichoderus cuspidatus species group. Regarding surface sculpturing and pubescence, as well as the shape of pronotum and mesonotum, laotius is very similar to Dolichoderus erectilobus. Yet, laotius is clearly distinct from the erectilobus holotype as well as from the remaining examined erectilobus material (North Thailand) by the characteristic shape of the propodeum: the coniform processes of the propodeum are much broader, longer and stouter than in erectilobus, and more strongly ascending and clearly overhanging the declivitous face. Furthermore, the laotius workers usually are larger and the declivity of the propodeum is more shining than in erectilobus. The shape of the mesonotum and particularly the shape of the strongly expanded, blunt corners of the propodeum resemble those of Dolichoderus pastorulus. Yet, the latter differs from laotius in several characters: the propodeum, in profile view, rises even higher, the body size is smaller, and at least the mesopleuron is more coarsely wrinkled.

Knowledge about the intraspecific variability is currently very limited.

Distribution
Laos and Northeastern Island.

Distribution based on Regional Taxon Lists
Oriental Region: Laos. Palaearctic Region: China.

Nomenclature

 *  laotius. Dolichoderus (Hypoclinea) laotius Santschi, 1920h: 170 (w.) LAOS. [Also described as new by Santschi, 1924c: 110.] See also: Dill, 2002: 46.

Worker
Dill (2002) - (Lectotype in brackets): HL 1.33-1.62 [1.57]; HW 1.25-1.62 [1.54]; EL 0.29-0.39 [0.34]; SL 1.24-1.51 [1.41]; AL 1.72-2.16 [2.09]; PnW 0.83-1.07 [1.00]; ML 0.53-0.68 [0.63]; MW 0.33-0.48 [0.41]; PpL 0.69-0.95 [0.82]; PpW 0.57-0.74 [0.62]; PpH 0.59-0.83 [0.78]; PpSW 0.49-0.72 [0.61]; PtW 0.43-0.58 [0.53]; TL 5.00-6.67 [6.33]. Indices: CI 91-102 [98]; OI 21-24 [22]; SI 88- 102 [92]; MI 137-173 [152]; PpSPpI 75-98 [89]; PpHLI 83-97 [95]; (n = 40).

Head: Dark-brown to black, scapus reddish to blackish-brown; ± evenly and densely punctate (= micro-imbricate); matt. Entire head (apart from frontal triangle) pubescent, particularly dense on mandibles, clypeus and frons; void of erect hairs. Head usually slightly longer than wide; suboval; s des strongly convex; occipital margin concavely emarginate.

Alitrunk: From reddish-brown to dark-brown and black. Apart from the ± smooth and shiny declivity of the propodeum, entire alitrunk evenly and densely punctate (= micro-imbricate), mall and pubescent; even mcsopleuron basically without a coarser rugose sculpturing (at most one to three short wrinkles in the upper half of the mesopleuron); erect hairs scarce and restricted to ventral face and coxae. Dorsal face of pronotum slightly convex, without distinct, edged lateral delimitations; shoulder corners rounded and very weakly developed. Mesonotum forming an evenly rounded, moderately ascending hump, which mostly lacks a median depression; processes at anterior margin of mesopleuron usually ± long and slenderly coniform. Propodeum in profile usually rising high, usually overtopping the mesonotum; upper corners of ascending dorsal face of propodeum expanded to broad, plump processes that point upwards and sidewards (fig. III - 11d); viewed in profile, the posterior margin of the ascending face distinctly overhanging the concavely curved declivity of the propodeum (fig. III - 11b).

Petiole: Punctate (= micro-imbricate) and pubescent. Scale usually entirely or only very weakly emarginate.

Gaster: Reddish-brown to brown-black to black. Evenly finely reticulate-punctate (= micro-imbricate); bearing a light-grey pubescence that is ± evenly arranged (also on 3rd tergite) rather than forming distinct cowlicks and a distinct median li ne of merging pubescence hairs; erect hairs only on sternites and gaster tip.

Type Material
Dill (2002) - Syntype workers, Laos, Hah Sampong (V. de Salvazza) [examined]; Laos, Muong Nya (Y. de Salvazza) (NMB) [examined]; Laos: Luang Prabang (Y. de Salvazza) [not examined]. [Also described as “new” in Santschi 1924 (= identical reprint of Santschi 1920).) One syntype here designated as Lectotype (NMB).

References based on Global Ant Biodiversity Informatics

 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Dill M. 2002. Taxonomy of the migrating herdsmen species of the genus Dolichoderus Lund, 1831, with remarks on the systematics of other southeast-Asian Dolichoderus. Pp. 17-113 in: Dill, M.; Williams, D. J.; Maschwitz, U. 2002. Herdsmen ants and their mealybug partners. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft 557: 1-373.
 * Jaitrong W., B. Guenard, E. P. Economo, N. Buddhakala, and S. Yamane. 2016. A checklist of known ant species of Laos (Hymenoptera: Formicidae). Asian Myrmecology 8: 1-32. DOI: 10.20362/am.008019
 * Liu C, B. Guénard, F Hita Garcia, S. Yamane, B. Blanchard, and E. Economo. New records of ant species from Yunnan, China. Submitted to Zookeys
 * 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
 * Shattuck S. O. 1994. Taxonomic catalog of the ant subfamilies Aneuretinae and Dolichoderinae (Hymenoptera: Formicidae). University of California Publications in Entomology 112: i-xix, 1-241.