Lordomyrma striatella (Mann)

Sarnat, E. M., 2006, Lordomyrma (Hymenoptera: Formicidae) of the Fiji Islands., Bishop Museum Occasional Papers 90, pp. 9-42 : 27-29

Lordomyrma striatella (Mann)

(Figs. 14, 15)

Rogeria striatella Mann , 1921: 454.

Description. Worker. TL 3.16-3.33, HL 0.71-0.75, HW 0.59-0.63, CI 0.83-0.88, SI 0.72- 0.79, REL 0.21-0.26, PSLI 0.82-1.00, MFLI 0.93-0.99, DPWI 0.92-1.01 (10 measured). A small dark reddish brown species with fine rugulae overlaying nearly all surfaces of the head, mesosoma, petiole and postpetiole; strongly defined antennal scrobes, short weakly downcurved propodeal spines, long hair and subtriangular petiole. In full face view, posterior margin of head evenly convex with rounded corners. Clypeus with one pair of well-defined carinae. Frontal with one pair of carinae in addition to the frontal carinae. Frontal carinae strongly produced, extending beyond posterior level of eye before integrating with dorsolateral rugoreticulum. Antennal scrobe narrow and well defined; bordered above by frontal carinae and below by thin carinae above eye; smooth and shining with a fine rugoreticulum between eye and antenna insertion. Eyes of moderate size. In profile, promesonotum relatively low, convex. Propodeal spines acute, slightly downcurved and divergent, in profile when measured from propodeal spiracles equal or shorter than the width of procoxa. Propodeal lobes weak triangles. Petiole slender and subtriangular with steep anterior and dorsal faces. Postpetiole taller than long, smaller than petiole, apex occurring anterior to midline. Mandibles smooth and shining with sparse, setigerous foveolae. Middorsum of head with tightly packed rugulae between frontal carinae except for a thin smooth median strip. Posterior margin of head including corners finely rugoreticulate. In oblique lateral view, sculpture surrounding eye rugoreticulate above, behind, and below; longitudinal carinae in front. Pronotum with rugoreticulate sides and dorsum; mesonotum mostly smooth dorsally. In dorsal view, propodeum smooth and shining with a distinct transverse carina proximal to the metanotal groove and transverse striations in between propodeal spines. Sides of mesonotum, metapleuron and propodeum overlain by fine, closely-spaced rugoreticulum. Procoxa with weak shallow impressions. Petiole and postpetiole finely rugoreticulate. Gaster smooth and shining dorsally and scalloped by shallow impressions basiventrally. All dorsal surfaces with long suberect to erect acuminate yellowish hairs, the longest of which are roughly equal to the length of the eye. Head, mesosoma and gaster dark reddish brown; appendages lighter.

Type Material. Syntypes, workers, Vanua Ava, Kadavu, Fiji (W.M. Mann) (NMNH) (examined).

Other Material Examined. FIJI: Beqa: Mt. Korovou, 1.5km WNW Dukuibeqa Village, 250-400 m, 23.v.2005, 18°24'32"S 178°07'10"E (E.P. Economo #93, #94); Mt. Korovou, 1.5 km WNW Dukuibeqa Village, 250-400 m, 23.v.2005, 18°24'32"S 178°07'10"E (E.P. Economo #93). Ovalau: 1.2 km NNW Draiba Village 17°41'S 178°49'E, 300 m, 24.vi.2003, sifted litter (A. Rakabula). Viti Levu: Nasoqo (W.M. Mann); 4.8 km NE Galoa Village 18°13'S 178°00'E, 300 m, 9.vi.2003, sifted litter (A. Rakabula); 7.5 km NE Vunisea Village 17°29'S 178°08'E, 300 m, 14.vii.2003, sifted litter (A. Rakabula).

Discussion. Lordomyrma striatella is a close relative of L. sukuna . Together, they are characterized by a narrow well developed antennal scrobe, a slender subtriangular petiole, striations on the propodeal declivity between the insertion of the spines, relatively short propodeal spines, weakly produced propodeal lobes, fine rugoreticulate sculpturing, long hairs on the dorsal surfaces, and dark coloration. Lordomyrma striatella can be easily separated from L. sukuna by the thin longitudinal striae running the length of its face within the bounds of the frontal carinae. While L. rugosa also has strong sculpturing between its frontal carinae, L. striatella can be distinguished by its more strongly developed and smooth antennal scrobe, more triangular petiole, smaller and more slender appearance, and weaker propodeal spines and lobes.

Distribution and biology. This species is recorded from collections scattered across Viti Levu, Ovalau, Beqa Island, and Kadavu. Many of the collections have been made from the leaf litter, and Mann reports them as being abundant from Kadavu where he found them nesting beneath stones. No collections of this species have been from above 400 m.