Lordomyrma polita (Mann) Sarnat, E. M., 2006

Sarnat, E. M., 2006, Lordomyrma (Hymenoptera: Formicidae) of the Fiji Islands., Bishop Museum Occasional Papers 90, pp. 9-42 : 21-23

Lordomyrma polita (Mann) , stat. n.

(Figs. 8, 9)

Rogeria tortuosa subp. polita Mann , 1921: 453.

Description. Worker. TL 3.32-3.86, HL 0.74-0.87, HW 0.64-0.76, CI 0.86-0.91, SI 0.75-0.79, REL 0.22-0.27, PSLI 1.13-1.46, MFLI 0.97-1.05, DPWI 0.91-1.09 (11 measured).

A medium-sized reddish brown species with long straight propodeal spines, short hair, shallowly impressed antennal scrobes, reduced facial sculpture and a robust petiole. In full face view, posteri- or margin of head evenly convex to slightly concave medially with rounded corners. Clypeus without strong carinae. Frontal carinae weakly carinate, terminating just posterior to level of eye. Antennal scrobe weakly impressed. Eyes relatively large. In profile, promesonotum modestly sized, convex. Propodeal spines acute, straight and divergent; when measured from spiracle in profile, one to one and a half times as long as width of procoxa. Propodeal lobes strong, long and upturned. Petiole robustly built; in profile anterior face of node concave and steeply sloped, posterior face convex and gently sloped, flat dorsally. Postpetiole with anterior and dorsal faces both evenly convex, apex occurring near midline. Mandibles triangular, smooth and shining with sparse setigerous foveolae. Middorsum of head smooth and shining with scattered setigerous foveolae; carinae mesad of frontal carinae. Frontal lobes with one to two pair of carinae in addition to the frontal carinae. In oblique lateral view, scattered punctures behind the eye, a few weak carinae above, below and in front of the eye; posterior corners of head with a few weak transverse carinae and punctures with elevated margins. Promesonotum varying from smooth and shining with a few weak carinae on sides and a few striations on dorsum to being overlain by thick, widely spaced rugae on sides and dorsum. In dorsal view, propodeum smooth and shining with a distinct transverse carina posterior to the metanotal groove; declivitous face smooth and shining. Sides of mesonotum, metapleuron, and propodeum overlain by coarse, widely spaced and occasionally intersecting rugae. Petiole and postpetiole coarsely rugoreticulate. Gaster smooth and shining. All dorsal surfaces with short and stout suberect to erect acuminate yellowish hairs, the longest of which are shorter than the length of the eye. Head and mesosoma reddish brown, gaster and appendages lighter.

Type Material. Syntypes, workers, 1 dealate queen, Nadarivatu, Fiji (W.M. Mann) (NMNH, MCZC) (examined).

Other Material Examined. FIJI: Koro: Mt. Nabukala, 5 km WSW Nasau Village, 17°18'45"S 179°23'17"E, 520 m, 15.iii.2005, nesting between epiphyte roots and tree trunk (E.M. Sarnat #1909, J. A. Schreiber). Vanua Levu: Mt. Vatudiri, 3km NW Waisali Village, 16°37'42"S 179°12'29"E, 641 m, 2.ix.2006, in dead tree fern (E.M. Sarnat #2389). Viti Levu: Navai forest, forestry camp, 11.vii.1997, in log (J. K. Wetterer #76, #94, #95); Koroyanitu National Park, Savione Falls, 2 km ESE Abaca Village, 17°40'34"S 177°33'01"E, 650 m,25.viii.2006, in log (E.M. Sarnat #2341); 1 km NNE Vaturu Dam, 17°44'36"S 177°40'09"E, 575 m, on log (E.M. Sarnat #2190).

Discussion. Lordomyrma polita is readily discernable from the other long-spined Fijian species, L. levifrons , by its short hairs. There exists considerable variation with respect to sculpture of the promesonotum among specimens of L. polita as currently defined. Whereas the type specimens from Nadarivatu together with a series collected from nearby Navai tend towards a more sculptured promesonotum and face, and a flatter petiole node, the series collected from the islands of Koro and Vanua Levu tend a smoother promesonotum and face, and a more rounded petiole node. Additionally, a male specimen from the Navai series has a smooth and shining metapleuron while that of the Koro male specimen is finely punctate. The single specimen collected from the Vuda province of Viti Levu appears intermediate between the Nadarivatu/Navai series and the Koro/Vanua Levu series. The allopatric pattern of these morphological traits does not allow for confident separation of species, thus all of the aforementioned series are considered here as belonging to a single species.

Distribution and Biology. Thus far, L. polita is known from the highlands surrounding Mt. Tomaniivi, the drier western forest near Vaturu Dam, the interior of Vanua Levu, and the island of Koro. This species has been observed nesting in logs in the Navai area and Vanua Levu, and nesting between epiphyte roots and a tree trunk on the island of Koro.