Lordomyrma vanua

Two collections have been made from the litter of Mt. Delaikoro on Vanua Levu.

Identification
Lordomyrma vanua, with its heavily rugose head and mesosoma, is similar to L. rugosa (Mann), but can be distinguished by its smooth forecoxae, smooth propodeal declivity, smooth anteriodorsal region of the promesonotum, broader and more widely-spaced rugae, and larger size. The other species with which L. vanua might be confused is L. striatella (Mann), from which it can be separated by its weaker antenna scrobe, broader and more widely spaced rugae, more well developed propodeal spines, more robust petiole and larger size. Despite its morphological resemblance to L. rugosa, molecular phylogenetic analyses place L. vanua as a closer relative to species such as L. tortuosa (Mann), L. striatella and L. vuda (Sarnat) (Lucky and Sarnat, unpubl. data). Thus far, L. vanua has been collected only twice, both times from the litter of Mt. Delaikoro on Vanua Levu.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Fiji.

Nomenclature

 *  vanua. Lordomyrma vanua Lucky & Sarnat, 2008: 42, figs. 1, 4, 5 (w.) FIJI IS.

Description
Worker. HL 1.03–1.19, HW 0.92–1.08, TL 4.78–5.27, CI 0.90–0.92, SI 0.65–0.83, REL 0.17– 0.21, MFLI 1.02–1.06, DPWI 2.38–2.40 (3 measured).

A large shiny black species with deep, widely spaced longitudinal rugae on head and mesosoma. In full face view, posterior margin of head evenly convex with gently rounded corners. Clypeus bearing one pair of weak carinae. Frontal carinae strongly produced, extending beyond posterior level of eye before integrating into dorsolateral rugoreticulum. Antennal scrobe lightly impressed, overlain by arcuate rugae near antennal insertions. In profile promesonotum large and dome-like. Propodeal spines strong, straight to upcurved and divergent. Propodeal lobes strong and tooth-like. Petiole subtriangular; in lateral view anterior face of node weakly concave and gently sloped, posterior face convex and gently sloped, weakly acuminate apex occurring at anterior angle of node. Postpetiole with anterior and dorsal faces evenly convex, apex occurring anterior to midline.

Mandibles smooth and shining with sparse, setigerous foveolae. Entire head overlain by thick, widely spaced rugae that become reticulated posteriorly. Frontal lobes with two pair of carinae in addition to the frontal carinae. Promesonotum smooth and shining anteriodorsaly transitioning into thick widely-spaced rugae posteriorly. In dorsal view, propodeum smooth and shining without a distinct transverse carina proximal to the metanotal groove. Forecoxae smooth and shining. Sides of mesonotum, metapleuron and propodeum overlain by coarse, widely-spaced rugae. Petiole and postpetiole coarsely rugoreticulate. Gaster smooth and shining. All dorsal surfaces with long suberect to erect acuminate yellowish hairs. Head, mesosoma and gaster black, appendages lighter.

Holotype. Worker, Mt. Delaikoro, 3.7km E Dogoru Village, Macuata Province, Vanua Levu, Fiji, 16°34.515'S 179°18.983'E, 699m, 31.viii.2006, sifted litter (E. P. Economo #62.08) (Fiji National Insect Collection, Suva). Paratypes. 1 worker, same data as holotype (National Museum of Natural History, Washington D.C.).
 * Type material.

The name vanua is a taken from the Fijian word for land, and for the only island where the species is currently known to occur, Vanua Levu, and is here used as a noun in apposition.
 * Etymology.