Holcoponera atrata

Only known from workers, nothing is known about the biology of Holcoponera atrata.

Identification
This is the largest-bodied member of the epinotalis group and besides Holcoponera major the only other species that is predominantly black in coloration. It is also the only species lacking ridges or denticles on the posterolateral corners of the propodeal declivity. H. major has a more triangular-shaped petiolar node in lateral view and an evenly convex margin on the clypeal lamella.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, Sulawesi.

Castes
Queens and males have not been collected.

Nomenclature

 * . Gnamptogenys atrata Lattke, 2004: 160, fig. 38 (w.) INDONESIA (Sulawesi).
 * Type-material: holotype worker, 4 paratype workers.
 * Type-locality: holotype Indonesia: Sulawesi Utara, G. Mogogonipa, 1000 m., 24.ix.1986 (no collector’s name); paratypes with same data.
 * Type-depositories: BMNH (holotype); BMNH, MIZA (paratypes).
 * Combination in Holcoponera: Camacho, Franco, Branstetter, et al. 2022: 11.
 * Status as species: Camacho, Franco, Branstetter, et al. 2022: 11.
 * Distribution: Indonesia (Sulawesi).

Worker
Lattke (2004) - Metrics. [Holotype] Paratypes (n = 2): HL [0.89] 0.91, 0.93; HW [0.71] 0.73, 0.75; ML [0.44] 0.43, 0.43; SL [0.63] 0.66, 0.68; ED [0.05] 0.08, 0.09; WL [1.16] 1.14, 1.11 mm. CI [0.81] 0.81, 0.80; SI [0.89] 0.91, 0.92; MI [0.62] 0.58, 0.58; OI [0.07] 0.11, 0.12. Head with anterior margin of clypeal lamella converging to form blunt obtuse angle in frontal view; clypeus longitudinally strigulose with median smooth area; clypeal lamella translucent, mostly smooth with sparse low strigulae. Pronotal dorsum with shallow piligerous punctae, each with one side deeper than other, roughly arranged in arches; rest of mesosomal dorsum mostly smooth medially, laterally punctate; pronotum strigulose-punctate laterally, punctae relatively shallow, arranged in arches; promesonotal suture feebly impressed; katepisternum strigose, anepisternum mostly smooth; mesopleural suture very broad with transverse ridges and strigulae; metapleuron relatively smooth anterodorsad and longitudinally costulate posteroventrad; lateral propodeal surface mostly smooth, propodeal dorsum slightly scabrose, mostly smooth medially; propodeal declivity mostly smooth, posterolateral ridge or denticle lacking; declivitous propodeal margin slightly convex in lateral view, propodeal spiracle mounted on tubular prominence that extends beyond declivitous margin; mesosoma in lateral view with very broadly convex dorsal margin.

Petiolar dorsum mostly smooth, sparsely punctate, punctae becoming larger laterally; postpetiole laterally with scalloped foveolate, postpetiolar dorsum sparsely punctate, posterior margin with brief longitudinal strigulae; fourth abdominal tergite sparsely punctulate, posterior margin with brief longitudinal striae; fourth abdominal sternite punctate over smooth ground sculpture. Fore coxa transversely strigulose; metacoxal tooth triangular. Dorsum of thorax and abdominal segments 1-4 with abundant erect to subdecumbent hairs. Head, mesosoma, petiole, and gaster black; mandibles, antennae, legs, and apex of propodeal spiracles and clypeal lamella brown.

Type Material
Holotype worker. Indonesia, Sulawesi Utara, 1000m, G. Mogogonipa, 24-ix-1986 (No collector data on the labels). Deposited in. Paratypes. Three workers in, 1w in from holotype series.

Etymology
The species name is derived from the Latin word for “dressed in black,” atratus, and alludes to the predominant body color of this ant.

References based on Global Ant Biodiversity Informatics

 * Lattke J. E. 2004. A taxonomic revision and phylogenetic analysis of the ant genus Gnamptogenys Roger in Southeast Asia and Australasia (Hymenoptera: Formicidae: Ponerinae). University of California Publications in Entomology 122: 1-266.