Polyrhachis (Aulacomyrma) breviata, Kohout, R. J., 2007

Kohout, R. J., 2007, Revision of the subgenus Aulacomyrma Emery of the genus Polyrhachis F. Smith, with descriptions of new species., Advances in ant systematics (Hymenoptera: Formicidae): Homage to E. O. Wilson - 50 years of contributions. (Memoirs of the American Entomological Institute 80), pp. 186-253 : 219-220

Polyrhachis (Aulacomyrma) breviata , new species

Figures 56, 59, 62

TYPE MATERIAL

HOLOTYPE: INDONESIA, IRIAN JAYA ( New Guinea : Neth . on data label), Wisselmeren (= Wissel Lakes ), Urapura , Kamo Valley , 03 º 55 ’ S, 136 º 15 ’ E, 1530 m, 11. viii. 1955, J. L. Gressitt (worker). PARATYPE: data as for holotype (worker). Type distribution: holotype in MCZC; paratype in QMBA .

WORKER

Dimensions: TL c. 4.23 - 4.43 (4.23); HL 1.15 - 1.22 (1.15); HW 1.09 - 1.12 (1.09); CI 92 - 95 (95); SL 1.22 - 1.25 (1.22); SI 112; PW 0.78 - 0.81 (0.78); MTL 1.12 (2 measured).

Anterior clypeal margin arcuate, shallowly emarginate medially; in profile clypeus weakly sinuate with shallowly impressed basal margin. Frontal carinae relatively short with laminate lobes. Sides of head convex in front of eyes, rounding behind into rather shallowly convex preoccipital margin. Eyes moderately convex, in full face view breaking lateral cephalic outline. Mesosoma rather short, somewhat antero-posteriorly compressed, dorsum completely immarginate. Pronotal dorsum widest at midlength; humeri armed with short, acute teeth. Promesonotal suture distinct; metanotal groove lacking. Mesonotal-propodeal dorsum rounding into sides and declivity in uninterrupted curve. Dorsal margin of petiole medially emarginate with a pair of acute intercalary teeth flanking emargination; additional pair of blunt, tooth-like projections, half way between intercalary teeth and rather short lateral teeth. Anterior face of first gastral segment truncate medially, rounding onto dorsal face of segment, without a distinct anterodorsal margin.

Mandibles finely longitudinally striate. Sculpture of head and mesosoma consisting of relatively fine striation; striae on head mostly longitudinal along moderately convex outline of head; V-shaped on clypeus and vertex, meeting along midline. Pronotal dorsum with transverse, strongly anteriorly bowed striae continued obliquely on sides. Striae on mesonotal-propodeal dorsum forming virtual semicircles or U-shaped patterns, continued obliquely along sides; posterior-most striae medially interrupted by rather smooth surface at base of propodeal declivity. Petiole with anterior face weakly transversely striate, medially overlaid by superficial, irregular, mostly vertical, reticulation; posterior face shagreened. First gastral segment more finely longitudinally striate, striae on dorsum converging anteriorly and merging into rather smooth, finely shagreened base.

A few erect or semi-erect, rather short, off-white or silvery hairs scattered on dorsum of head and mesosoma, a few hairs arising from leading edge of antennal scapes and dorsal margin of petiole. Propodeal declivity bordered laterally with short, semi-erect, silvery-gray hairs, that extend onto propodeal lobes. Somewhat longer, yellowish to golden hairs around apex and venter of gaster, almost completely absent from dorsum. Appressed pubescence virtually absent, except on gastral dorsum where it is silvery to golden and partly obscures underlying sculpture.

Black, including antennal scapes and coxae. Funiculi medium reddish brown with proximal portion of basal segments bordered black. Legs mostly light to medium yellowish brown; distal half of femora, proximal end of tibiae and basal segment of tarsi dark reddish brown.

Sexuals and immature stages unknown.

ETYMOLOGY

Name derived from the Latin word brevior, meaning shorter, referring to the distinctly short body.

REMARKS

P. breviata is rather similar to gressitti , with both species featuring a distinctly shortened body and similar configuration of the petiole, including an emarginate dorsal margin bordered by intercalary teeth. However, gressitti is easily recognized by its very high propodeal declivity and the direction of the striae that are mostly longitudinal on the vertex. In breviata the striae on the vertex are distinctly V-shaped and meet along the midline. This species also somewhat resembles annulata with distinguishing characters listed in the remarks section under that species.