Polyrhachis (Aulacomyrma) roomi, 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: 236-237

publication ID


persistent identifier


treatment provided by


scientific name

Polyrhachis (Aulacomyrma) roomi

new species

Polyrhachis (Aulacomyrma) roomi   HNS   , new species

Figures 100, 103, 106


HOLOTYPE: PAPUA NEW GUINEA, Northern Prov., Sangara , 18. xii. 1971, P. M. Room (worker). PARATYPES: data as for holotype (4 workers). Type distribution: holotype in ANIC, 1 paratype each in BMNH, CASC, MCZC and QMBA   .


Dimensions: TL c. 6.05 - 6.60 (6.60); HL 1.50 - 1.72 (1.56); HW 1.28 - 1.50 (1.34); CI 85 - 88 (86); SL 1.56 - 1.72 (1.59); SI 115 - 126 (119); PW 1.03 - 1.18 (1.06); MTL 1.53 - 1.68 (1.59) (5 measured).

Anterior clypeal margin distinctly emarginate medially, dentate on each side of emargination; clypeus with weakly raised longitudinal carina, almost straight in profile; basal margin weakly impressed and indicated laterally by faint line breaking cephalic sculpture. Frontal carinae with strongly sinuate and distinctly raised laminate lobes. Sides of head convex. Eyes virtually flat, situated well forward on sides of head; inner margins somewhat sunk into shallow concavity in cephalic sculpture; not or only just reaching lateral cephalic outline in full face view. Mesosoma with pronotal and propodeal dorsa laterally immarginate; mesonotal dorsum with outermost striae forming short margin. Pronotal humeri armed with short, laterally and anteriorly directed, horizontal spines. Promesonotal suture rather shallow, indicated by change in direction of sculpture; metanotal groove lacking. Propodeal dorsum separated from declivity by faint posterior border that, viewed from behind, forms inverse ‘ V ’ terminating laterally in small denticles. Dorsal petiolar margin with pair of acute intercalary teeth medially, shallowly emarginate between them; laterally margin somewhat jagged, lateral teeth acute, weakly upturned. Anterior face of first gastral segment shallowly concave, narrowly rounding onto dorsum of segment.

Mandibles densely, rather finely, longitudinally striate. Dorsum of head with mostly regular striae; longitudinal and anteriorly converging on clypeus, obliquely curving from sides of head towards basal clypeal margin, transverse and anteriorly bowed on vertex with outermost striae converging towards central area between frontal carinae. Pronotal dorsum mostly regularly, transversely striate; striae curving vertically onto sides. Striae on mesonotal-propodeal dorsum transverse, bowed posteriorly into open U-shapes; sides with striae more-or-less horizontal. Petiole and gaster finely shagreened.

Dorsum of head and mesosoma with medium length, mostly erect, off-white or yellowish hairs; hairs somewhat posteriorly curved and golden on gastral dorsum, distinctly longer along sternites and on gastral apex. Appressed pubescence much reduced on head and mesosomal dorsum, only patches of sparse, off-white or silvery pubescence on sides of propodeum, along propodeal declivity, petiole and coxae. Golden and rather dense gastral pubecence mostly confined to dorsum of first segment, not completely concealing underlying sculpture.

Black; most of antennal scapes, basal half of first funicular segment, joints of femora and tibiae, bases of basal tarsal segments and gaster dark to very dark reddish-brown. Mandibular masticatory border, basal and distal ends of antennal scapes, funiculi and most of legs light to very light reddish-yellow.

Sexuals and immature stages unknown.


Named in honour of the collector, Dr Peter M. Room of CSIRO, Division of Entomology, Indooroopilly, Queensland, Australia, who collected scores of ants, many new to science, during the years of his appointment as an agricultural entomologist in Papua New Guinea.


This species is easily recognisable by its relatively large size.


Australia, Australian Capital Territory, Canberra City, CSIRO, Australian National Insect Collection


United Kingdom, London, The Natural History Museum [formerly British Museum (Natural History)]


USA, California, San Francisco, California Academy of Sciences


USA, Massachusetts, Cambridge, Harvard University, Museum of Comparative Zoology


Australia, Queensland, South Brisbane, Queensland Museum


Commonwealth Scientific and Industrial Research Organisation


Australia, Commonwealth Scientific and Industrial Research Organisation


Australia, Commonwealth Scientific and Industrial Research Organisation


Australia, Commonwealth Scientific and Industrial Research Organisation


Australia, Commonwealth Scientific and Industrial Research Organisation


Australia, Commonwealth Scientific and Industrial Research Organisation