Polyrhachis (Aulacomyrma) pelecta, 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 : 233-234

Polyrhachis (Aulacomyrma) pelecta , new species

Figures 91, 94, 97

TYPE MATERIAL

HOLOTYPE: PAPUA NEW GUINEA, Karubaka, Swart Valley , 03 º 35 ’ S, 138 º 30 ’ E, 1500 m, 11. xi. 1958, J. L. Gressitt (worker). PARATYPE: data as for holotype (1 worker). Type distribution: holotype in MCZC; paratype in QMBA .

WORKER

Dimensions (holotype cited first): TL c. 5.49; HL 1.47, 1.43; HW 1.28, 1.28; CI 87, 89; SL 1.50, 1.50; SI 117, 117; PW 1.12, 1.12; MTL 1.43, 1.40 (2 measured).

Anterior clypeal margin arcuate, entire; slightly sinuate in profile. Frontal triangle indistinct. Frontal carinae strongly sinuate, raised, with laminate lobes; central area relatively wide with rather distinct longitudinal carina formed by strongly raised median stria. Sides of head gently convex, only weakly converging anteriorly. Eyes convex, in full face view breaking lateral cephalic outline. Pronotal humeri armed with broad-based triangular teeth, that are shallowly concave dorsally between distinctly raised margins; lateral margins continued for some distance before merging with dorsal striae along sides. Promesosonal suture distinct; metanotal groove lacking. Mesonotal dorsum only partially marginate. Propodeal dorsum immarginate, with posterior angles weakly indicated. Petiole relatively narrow, as wide as high, with dorsal margin somewhat jagged; lateral spines short, slender, directed outwards and only slightly curved backwards. Anterior face of first gastral segment only shallowly concave medially at base.

Sculpture of head consisting of regularly spaced striae; mostly longitudinal, converging medially and anteriorly on clypeus and between frontal carinae. Pronotal dorsum with broadly open, inverse V-shaped striae. Sculpture of mesonotal-propodeal dorsa differing between holotype and paratype; striae in holotype forming incomplete semicircles, open inversely U-shaped posteriorly; in paratype striae strongly converging posteriorly and meeting along midline in V-shaped pattern. Dorsum of first gastral segment microscopically shagreened, becoming finely longitudinally striate towards sides.

Short, erect or semierect, off-white or yellowish hairs present in various densities on most body parts, except inferior edge of antennal scapes. Rather sparse, appressed pubescence everywhere; more dense on coxae and anterior face of petiole and propodeal declivity that is bordered laterally by very short, greyish, semierect fine hairs. Gastral dorsum with light cover of silvery pubescence not concealing underlying sculpture.

Black; antennae and legs dark to very dark reddish-brown. Mandibular masticatory borders, funiculi, tibiae, except proximal ends, and distal tarsal segments distinctly lighter.

Sexuals and immature stages unknown.

ETYMOLOGY

Name derived from the Latin pellax, meaning deceitful or decoy, in reference to its close resemblance to P. geometrica .

REMARKS

P. pelecta is rather close to P. geometrica but differs in having the pronotal teeth broad-based, the lateral propodeal margins feebly dentate posteriorly, the dorsal margin of the petiolar node more-or-less entire and the first gastral segment with very fine striations confined to its sides. In contrast, the pronotal teeth in geometrica are distinctly smaller and more acute, the propodeum smoothly rounds into the declivity, the dorsal margin of petiolar node is distinctly medially emarginate and the whole surface of first gastral segment is distinctly and finely, striate.