Fulakora lurilabes

A ground dwelling species.

Identification
Modified from Lattke (1991): The dense anterior sculpturing on the cephalic dorsum separates this species from Stigmatomma elongatum (Santschi) and Stigmatomma monrosi Brown, which are predominantly smooth and shining. Stigmatomma lurilabes is apparently sympatric with S. elongatum in northern Argentina, and S. monrosi is an endemic Chilean ant. Stigmatomma armigerum Mayr is larger in size, with proportionally much larger gular teeth, and larger punctures and more prominent rugae on the cephalic dorsum than S. lurilabes. An apparently exclusive character that separates S. lurilabes from the rest of New World Stigmatomma is the spot on each posterolateral propodeal face.

Key to Stigmatomma of the New World

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil, Colombia, Ecuador, Peru, Trinidad and Tobago, Venezuela.

Lattke (1991): Most of the records for this species are concentrated in northern South America, with the exception of a specimen from northern Argentina and the Peruvian record. The large gaps in its distribution is unexpected considering the fact that this species is apparently not uncommon, judging from the number of specimens available for study.

Biology
Lattke (1991): The holotype nest consisting of two queens and 17 workers was found beneath a stone in a coffee plantation. Beneath the same stone and apparently with overlapping nest limits was a colony of Basiceros disciger (Mayr). Other samples come from leaf litter samples taken mostly in humid and wet forests, between elevations of 70-1000 m. A Peruvian specimen was captured in clay soil at the base of a large tree growing in mature "tierra firme" forest.

Castes
Males of this species have not been collected.

Nomenclature

 *  lurilabes. Amblyopone lurilabes Lattke, 1991c: 2, fig. 2 (w.q.) VENEZUELA. Combination in Stigmatomma: Yoshimura & Fisher, 2012: 19.

Worker
Holotype (paratypes) dimensions: HL 0.76 (0.72-0.80), ML 0.54 (0.50-0.56), HW 0.60 (0.57-0.70), SL 0.34 (0.35-0.40), WL 0.90 (0.94-1.00) mm, CI 0.79 (0.79-1.00), SI 0.57 (0.57-0.63); n=5.

Head in full face view with straight to gently convex posterior border, sides slightly convex and diverging anterad. Gular teeth small and acute. Anterior clypeal border convex, usually with 6 teeth: median pair may be separate or fused to a variable degree, single tooth on each side, and heavy, usually bidentate lateral teeth. Sometimes a single tooth may be present between median teeth and lateral tooth; one specimen with small denticle between median teeth. Inner mandibular margin with large basal triangular tooth, smaller subbasal tooth, series of four basally fused double teeth. A small preapical, usually bicuspid tooth present before long, sharp apical tooth. Dorsal and ventral mandibular surfaces longitudinally rugose. Scape with longitudinal rugulae and low oval depressions.

Cephalic dorsum densely reticulate-punctate and with noticeable longitudinal rugulae on anterior one-fourth to one-third of head, much weaker rugulae, sometimes barely discernible, extend caudad toward vertex. Some oblique striae on gular area. A narrow longitudinal median strip of smoother sculpture present, extending from behind frontal carinae to vertex. Microsculpture on posterior cephalic dorsum coriarious. Head ventrum smooth, with scattered piligerous punctures; occiput smooth and shining with some punctures. Eyes consisting of single ommatidium situated behind cephalic midlength.

Mesosoma laterally with nearly flat dorsal margin, promesonotal suture marked, metanotal suture totally effaced. Propodeal dorsum slightly higher than rest of mesosomal dorsum, broadly curving into gently convex declivitous face. Propodeal dorsum smooth and shining, with scattered punctures, declivitous face glabrous. Mesosoma widest at pronotum, narrowest at mesonotum, which is transverse; propodeum has broadly convex sides that diverge caudad. Pronotal sides smooth and shining with scattered punctures. Metepisternal and lateral propodeal faces glabrous, except for inferoposterior transverse striae with some punctures below propodeal spiracle. Katepisternum with transverse rugulae, anepisternum smooth and shining.

Petiole laterally with straight to slightly concave anterior face, meeting the flat to slightly convex dorsal face at right angle. Petiole dorsally longer than wide, postpetiole transverse. Subpetiolar process elongate, with slightly concave inferior margin. Gaster smooth and shining with scattered piligerous punctures. Femora and tibia, especially middle and hind, laterally compressed. Apex of fore tibia with large pectinate spur, mesotibia with small slender spur and metatibia with large curved pectinate spur and an accompanying smaller, more slender one. Empodia present, claws simple.

Head very dark brown; antennae, mandibles, petiole, and posterior pronotal margins dark ferruginous yellow. Mesosoma mostly black; gaster light to dark yellowish-brown. Legs ferruginous yellow. Lateroposterior corners of propodeum with oblong patch usually testaceous to dark ferruginous yellow. Body with short standing hairs on mesosoma, longer on anterior face of pronotum, posterior margin of propodeal dorsal face and toward apex of gaster. Pubescence mostly sparse and appressed.

Queen
HL 0.72, 0.71; ML 0.44, 0.47; HW 0.58, 0.56; SL 0.35, 0.35; ED 0.10, 0.11; WL 1.00, 1.00 mm; CI 0.81, 0.79; MI 0.76, 0.84; SI 0.60, 0.63.

Two paranidotypes with same collection data as holotype. Deposited in IZAV. Significant differences from the workers are the usual: presence of compound eyes, ocelli, and more mesosomal development, plus wing stumps. Punctures of cephalic dorsum are shallower than in worker, and the longitudinal rugulae are more noticeable. Pilosity more abundant than worker.

Type Material
Holotype worker: VENEZUELA, Portuguesa, 6 km SE Biscucuy, 9°18'N 70º01'W, 1000 m, 18-VIII-1983, J. Lattke, leg. no. 438. Deposited in. Paratypes: (1) Eleven nidoparatypic workers and queen with the same collection data as the holotype. One worker each in, ,.

Etymology
The name of this species is a conjugation of the Latin adjective for pale yellowish, luridus, and the Latin noun for spot, labes. The name alludes to the unique propodeal spots.

Additional References

 * Yoshimura, M. & Fisher, B.L. 2012. A revision of male ants of the Malagasy Amblyoponinae (Hymenoptera: Formicidae) with resurrections of the genera Stigmatomma and Xymmer. PLoS ONE 7(3):e33325 (doi:10.1371/journal.pone.0033325).