Lordomyrma reticulata Lucky and Sarnat

Lucky, Andrea & Sarnat, Eli M., 2008, New species of Lordomyrma (Hymenoptera: Formicidae) from Southeast Asia and Fiji, Zootaxa 1681, pp. 37-46 : 39-40

Lordomyrma reticulata Lucky and Sarnat , sp.nov.

( Figs. 1–3 )

Description. Worker. HL 0.78–0.81, HW 0.75–0.79, TL 3.47–3.92, CI 0.94–0.99, SI 0.72–0.75, REL 0.19– 0.20, PSLI 1.14–1.36, MFLI 0.89–0.99, DPWI 1.00–1.13 (7 measured).

Head subquadrate, longer than wide, with sides of head evenly convex. Posterior margin evenly convex in full face view and posterolateral corners gently rounded. Clypeus convex, bearing a pair of strong carinae that converge centrally and diverge anteriorly and posteriorly, forming an hourglass shape. Antennal scrobe broad and strongly impressed, bordered entirely by a distinct raised ridge. Scape not extending beyond posterior margin of head. Promesonotum in profile rounded and domelike. Metanotal groove strongly impressed. Declivitous face of propodeum concave. Dorsal face of propodeum in profile flat to slightly convex. Propodeal spines strong, triangular and straight, though slightly downcurved in profile and divergent distally in dorsal view. Propodeal lobes stout and triangular. In lateral view, peduncle of petiole thick. Petiolar node in dorsal view as broad as long. Petiole taller than long, with anterior face slightly concave and dorsal face convex. Both anterior and posterior faces of postpetiole convex, postpetiole shorter than petiole, highest point anterior to midpoint and ventral side possessing two transverse ridges with setae emerging between them.

Head and mesosoma covered in a raised, closely-packed rugoreticulum with honeycomb-like regularity. Sculpture of posterior margin of head rugoreticulate. Mandibles striate. Clypeus rugose. Rugoreticulae on median portion of face continue onto frontal lobes. Scrobe delicately rugose with a few weak carinae near antennal insertion. Scape finely sculptured, venter with cavity for reception of funiculus. Forecoxae delicately rugoreticulate, finer than head and body sculpture, similar to surface texture of scrobe. All other coxae and legs finely sculptured. Venters of femora excavated to receive tibiae. Anepisternum, katepisternum, metapleuron, and pronotum coarsely rugoreticulate, but with less regular intersections than on head. In dorsal view declivity of pronotum smooth and shining with a few weak lateral striae. Petiole and postpetiole strongly rugoreticulate above and on sides, but more delicately sculptured ventrally. Petiole excavated ventrally. Gaster rugoreticulate both dorsally and ventrally, but with shallower sculpture than on mesosoma and head, and becoming finer towards the posterior margin of each gastral tergite.

Eyes hairless and small, longer than wide. Pilosity on head longer than length of eye. Standing pilosity pale yellow, common on most of body. Color of head, body and gaster reddish-brown, appendages only slightly paler than body.

Type Material. Holotype. Worker, MALAYSIA: Sabah: Danum Valley, 5°01'N 117°49'E 14.ix.2006 (NBT C88S4-1, CASENT#0012191) (Thornton, et al.). Paratype. Three workers, same data as holotype (CASENT#0012192-0012194); two workers, same data as holotype, except NBT C88S4-4 (CASENT#0012195, 0012196); one worker, same data as holotype, except NBT C88S4-2 (CASENT#0012197).

All seven workers were obtained from leaf litter in lowland dipterocarp rain forest in Sabah, Malaysia, in a selectively logged tract adjacent to the Danum Valley Conservation Area (Coupe 88). Sifted litter samples were extracted using Mini-Winkler extractors by Noel B. Tawatao (NBT) with permission of the Danum Valley Field Centre. Holotype and three paratypes have been deposited at Universiti Malaysia Sabah. One paratype is deposited at each of the following locations: the Australian National Insect Collection in Canberra, the Harvard Museum of Comparative Zoology and the California Academy of Sciences.

Etymology. The name reticulata refers to the cuticular sculpture on this species, which forms deep reticulations on the head, mesosoma and gaster.

Discussion. Lordomyrma reticulata can be recognized by the deep and regular reticulating sculpture on the head and mesosoma, which becomes shallower on the gaster both dorsally and ventrally. The clypeus is distinctly rugose and convex, with a pair of strong carinae that converge centrally and diverge anteriorly and posteriorly, forming an hourglass shape. The sculpture of the broadly impressed scrobe and of the forecoxae is finely rugoreticulate. Scapes and legs are shallowly sculptured rather than smooth and shining. The undersides of the femora, petiole and scapes bear longitudinal concavities, presumably for reception of retracted limbs. Pilosity on head and body is pale and erect to suberect.

Of all described congeners L. reticulata most closely resembles the Japanese L. azumai (Santschi) , which is also heavily sculptured in a regularly intersecting rugoreticulate pattern on head, alitrunk and gaster. Lordomyrma reticulata is distinguished by the shape of the petiole, as the peduncle is clearly shorter than the length of the node whereas L. azumai presents a distinctly elongate peduncle. Among other undescribed Lordomyrma known to occur in Borneo L. reticulata would appear to be distinguished by the combination of sculpturation on the forecoxae, the regular rugoreticulations on the gaster and pale yellow standing pilosity common on most of the body (R.W. Taylor, pers.comm.).

Figures

FIGURE 1. Distribution of described Lordomyrma species.

FIGURE 2. Lordomyrma reticulata, head.

FIGURE 3. Lordomyrma reticulata, profile.