Fulakora orizabana

The holotype was taken by E. O. Wilson on Pica Orizaba, Veracruz, Mexico, on August 24, 1953. The worker was found under a large mossy rock in an open grassy strip along the trail between La Perla and Rancho Somecla, on the southern slope of the mountain, at about 2700 to 2800 m. altitude. At this altitude, the original forest cover is mainly broadleaf temperate trees, with Carpinue abundant and some pines.

Identification
The tiny size and yellowish color distinguish this species from other U.S. Stigmatomma. The only species from the Americas that is smaller, Stigmatomma degeneratum is very different in antennae and sculpture. In the field, S. orizabanum might be confused with a species of Prionopelta (Brown 1962), although no Prionopelta species is known from the U.S. range of S. orizabanum.

Distribution
Highlands of southern Mexico to lowland Choco, Colombia (Brown 1960, Lattke 1991). Costa Rica: wet forests from 50-1700m elevation, cordilleras north to south. A single specimen has been collected from southeast Arizona, United States.

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Colombia, Costa Rica, Guatemala, Honduras, Mexico, Panama.



Biology
The type specimen of this sepcies was found at an elevation of 2700 to 2800 m, under a rock beside a trail in a Mexican forest (Brown 1960). A few additional specimens were found under a rotten branch in rain forest on Barro Colorado Island (Brown 1962). A specimen from Arizona was found by a student in an ant course held at the Southwest Research Station in Portal, Arizona. The ant was found under a large rock in a dry, open forest of oaks and pines. It seems, at first, a little unlikely that these three occurrences from such different habitats all represent the same species. Stigmatomma pallipes, however, shows a similar range of habitats, from northern conifer forests to subtropical, dry scrub.

Nomenclature

 *  orizabanum. Amblyopone orizabana Brown, 1960a: 190 (w.) MEXICO. Combination in Stigmatomma: Yoshimura & Fisher, 2012: 19. Senior synonym of tropicalis: Lattke, 1991c: 5.
 * tropicalis. Amblyopone tropicalis Brown, 1962a: 73 (w.q.) PANAMA. Junior synonym of orizabanum: Lattke, 1991c: 5.

Worker
Holotype worker: TL 2.7, HL 0.58, HW 0.48 (or 83), WL 0.74, petiole L 0.26, petiole W 0.29, scape L (without basal neck) 0.31, straightline outside L of left mandible 0.34 mm. A very small, yellow member of the "Fulakora group" with dorsum of head densely and evenly reticulate-punctate and opaque or nearly so. The habitus and shape of head, body and appendages are all substantially as in Stigmatomma smithi, although the posterior occipital border is more strongly concave in the middle in orizabana. Also, the mandibles are more slender in orizabana, and can close tightly against the clypeal apron (as in the holotype). Clypeal apron convex, with 4 truncate teeth socketed on low tubercles in the middle (median pair smaller, bases fused), flanked by broader corner teeth on each side; the latter cannot be seen clearly, and may possibly be subdivided. 'I'he mandibular dentition is difficult to see, but it appears to consist of a triangular basal tooth or lamella, 4 sharp double teeth, and a reclinate, acute subapical tooth in addition to the slender apical tooth. The inner borders are convex. Antennae much as in S. smithi.

Alitrunk constricted at the narrow, transverse mesonotum, which is continuous with the propodeal dorsum; metanotal groove almost obsolete, visible only in certain lights. Petiolar node with a vertical anterior face, convex in both directions; dorsum only weakly convex. Petiole and postpetiole about equal in length; abdominal IV slightly longer. Ventral process of petiole with a small angular anterior lobe and a larger, bluntly subtriangular posterior lobe that slopes upward gradually posteriad. Gastric apex not compressed; sting stout.

Mandibles and lower sides of posterior half of alitrunk longitudinally striolate. Underside of head densely reticulate-punctate, but weakly shining. Rest of body, including legs, scapes and frontal groove, smooth and shining, with numerous, spaced small piligerous punctures, best seen on pronotum and petiole. Pilosity fairly abundant, but very short and mostly oblique; longer hairs on mandibles and gastric apex. Color light ferruginous yellow.

Lattke (1991). Dimensions: HL 0.58-0.62, ML 0.380.42, HW 0.48-0.55, SL 0.31-0.34, WL 0.70-0.79mm, CI 0.81-0.90, MI 0.76-0.88, SI 0.58-0.65; n= 8.

Queen
Brown (1962), for the synonymized S. tropicalis - Paratype female (dealate) : TL 3.1, HL 0.65, HW 0.57 (CI 88), WL 0.91, petiolar node L 0.26, W 0.38, scape L 0.37, greatest diameter of compound eye 0.11 mm. Similar to the holotype worker, but with the usual differences of caste: fairly large compound eyes (no eyes could be detected in the worker), ocelli developed and with blackened calli, wing stumps present and blackened; meso- and metathoracic flight sclerites well developed, but rather flat, continuing the weakly convex surface of the alitrunk without major interruption. As usual for females of this genus, the petiole and gaster are relatively a little wider than in the worker, and the head, while still light ferruginous, is a trifle darker than in the worker. Alitrunk also rather coarsely and closely punctate above, but still distinctly shining.

Etymology
After the type locality, Pico de Orizaba.