Polyrhachis (Aulacomyrma) wilsoni, 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 : 214-215

Polyrhachis (Aulacomyrma) wilsoni , new species

Figures 47, 50, 53

TYPE MATERIAL

HOLOTYPE: PAPUA NEW GUINEA, Huon Pen., lower Busu R. , 5. v. 1955, lowland rf., E. O. Wilson # 950 (worker). PARATYPES: data as for holotype, but 3. v. 1955, E. O. Wilson # 895, 969 (3 workers) and 9. v. 1955, E. O. Wilson # 984 ) (worker) ; Bulolo , 3000 ft, 19. xii. 1970, rf., B. B. Lowery (4 workers) ; W . Bulolo , 2500 ft, 22. xii. 1970, rf., B. B. Lowery (3 workers). Type deposition: holotype and 2 paratypes in MCZC; 2 paratypes each in QMBA, ANIC, BMNH and CASC .

WORKER

Dimensions: TL c. 4.13 - 4.84 (4.59); HL 1.12 - 1.28 (1.25); HW 1.00 - 1.15 (1.09); CI 87 - 92 (87); SL 1.22 - 1.31 (1.28); SI 114 - 122 (117); PW 0.94 - 1.09 (1.00); MTL 1.09 - 1.22 (1.22) (12 measured).

Anterior margin of clypeus arcuate with very shallow notch medially; in profile clypeus weakly convex. Sides of head in front of eyes gently converging anteriorly. Eyes convex, clearly breaking cephalic outline in full face view. Frontal carinae distinctly raised, sinuate; frontal area relatively wide, with short median carina that merges posteriorly into cephalic sculpture. Mesosoma marginate along entire length. Pronotal humeri armed with broad-based, triangular, blunt, teeth. Mesonotal and propodeal dorsa fused, with lateral margins deeply emarginate, terminating in very long, outwardly curved spines, their posterior margins continued as tranverse, deeply inwardly bowed ridges, that meet medially and separate propodeal dorsum from declivity. Petiole with sharp, dorsal margin, shallowly indented medially; lateral spines acute and curved backwards, their tips slightly upturned. Anterior face of first gastral segment concave, accommodating posterior face of petiole; anterodorsal margin of concavity distinct medially, but not raised above dorsal face of segment.

Sculpture of head, mesosoma and sides of gaster consisting of regularly spaced striae, mostly longitudinal on dorsum of head and sides of gaster, anteriorly converging on pronotal dorsum, converging posteriorly and joining along midline on mesonotal and propodeal dorsa. Propodeal declivity, petiole and dorsum of first gastral segment shagreened.

Abundant, yellowish, semi-erect to erect hairs present on all body surfaces and appendages, longest hairs almost as long as greatest diameter of eye. Hairs absent from inferior edges of scapes and dorsal surfaces of femora. Body with mostly off-white or yellowish, appressed pubescence, denser and silvery on metapleuron and reddish on gastral dorsum.

Black, with antennal scapes, distal portions of femora, proximal and distal ends of tibiae and basal segments of tarsi dark to medium brown; funiculi and rest of legs distinctly lighter, medium to light yellowish brown or reddish-yellow.

Sexuals and immature stages unknown.

ADDITIONAL MATERIAL EXAMINED

PAPUA NEW GUINEA: Adelbert Mts, Wanuma, 800 - 1000 m, 26. x. 1958 (J. L. Gressitt) (w); Wau Gorge, 3000 ’, rf., 30. xii. 1970 (B. B. Lowery) (w); ditto, 7. i. 1971 (B. B. Lowery) (w).

ETYMOLOGY

Named in honor of Prof. Edward O. Wilson of Harvard University, who collected many new Aulacomyrma species during his extensive field work throughout Papua New Guinea.

REMARKS

A remarkable species, easily distinguished from all other known members of the subgenus by the very elongate, strongly divergent, propodeal spines.