Polyrhachis lama

Kohout (1994) - The known distribution of the viehmeyeri-group is from the Moluccas through Papua New Guinea to the Solomon Islands and northern Australia (Kohout, 1990) but this could be underestimated. With the description of P. lama it appears that the group was in the past more widely distributed and, perhaps, lama is an isolated relict. The undeniable similarity between P. lama and the viehmeyeri-group prototype shows that both probably derived from the same ancestral stock. As noted earlier (Kohout, 1990:506), most of this group exhibit variability in the length of pronotal spines even within the same population. Their complete absence and replacement by forward produced carinae, as seen in lama, demonstrates their variability to the extreme and can be interpreted as a product of an independent development of the species in isolation.

Identification
A member of the P. veihmeyeri group.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, Philippines. Oriental Region: Tibet. Palaearctic Region: China.

Nomenclature

 *  lama. Polyrhachis lama Kohout, 1994b: 137, fig. 1 (w.) TIBET. See also: Maschwitz, Dorow, Buschinger & Kalytta, 2000: 27.

Worker
(holotype cited first): TL c. 8.11, 8.32-8.72; HL 1.93, 1.87-2.03; HW 1.50, 1.47-1.56; CI 78, 75-79; SL 2.31, 2.21-2.40; SI 153, 150-155; PW 1.03, 0.97-1.06; MTL 2.97, 2.87-3.07 (5 measured).

Clypeus with deeply impressed basal margin; median longitudinal carina distinct anteriorly, indistinct posteriorly; median portion of anterior margin dentate laterally. Median ocellus rudimentary, lateral ocelli lacking. Pronotum unarmed; humeri produced into distinct, forward converging dorso-lateral carinae almost reaching the anterior pronotal margin. Promesonotal suture well impressed, metanotal groove rather ill defined. Propodeal spines well elevated, only slightly divergent. Dorsum of petiole convex, anterior and posterior margins obsolete; spines well elevated, divergent.

Clypeus, frontal and lateral areas of head, lateral branches of mesosoma and petiole moderately rugose; rugosity increasing dorsally and posteriorly with dorsa of head and mesosoma fairly coarsely vermiculate-rugose. Gastral dorsum opaque, striate-rugose, with sculpture progressively less distinct posteriorly.

Moderately long, yellowish and reddish bristlelike hairs fairly dense on all body surfaces, including appendages. Silvery pubescence, of distinctly shaggy appearance, rather dense, except on promesonotal dorsum where it is somewhat less abundant.

Generally dark reddish brown with head, mesosoma and petiole on dorsal aspect piceous. Mandibles, appendages and gaster a shade lighter.

Queen
TL c. 9.07; HL 1.96; 1.53; CI 78; SL 2.28; SI 149; PW 1.71; MTL 2.97 (1 measured).

Besides the usual characters identifying full sexuality, the general appearance of the available single female resembles the worker very closely. Pronotal humeri with short, ill-defined carinae. Propodeal and petiolar spines shorter, the former slightly, the latter rather more divergent. Sculpturation similar to that of worker, with density increasing from moderately rugose to fairly coarsely vermiculate-rugose, namely on the head and mesoscutum, contrasting sharply with that on mesoscutellum where it is distinctly less coarse with somewhat granular appearance. Bristle-like pilosity is definitely more dense than in the worker and abundant shaggy pubescence almost obscures the underlying sculpturation.

Type Material
Holotype: Tibet (=Xizang Zizhiqu, China). 'Deutsche Tibet-Expedit. 1938-39 (E. Schafer)' (worker). Paratypes: data as for holotype (4 workers, 1 dealate female). All in the Forschungsinstitut Senckenberg; paratype worker in Queensland Museum.