Cardiocondyla argyrotricha

So far known from six localities west of the Wallace Line on Tioman island, Borneo and Luzon from sea level up to 380 m.

Schmidt et al. (2014), Frohschammer (2015) and Schmidt & Heinze (2018) reported the species to be functionally monogynous, to show intranidal mating, and to develop only wingless ergatoid males with sickle-shaped mandibles which fight to monopolize mating. Once the dominant queen has died, the first eclosing gyne will mate and prevent younger gynes from becoming fertile (Schmidt et al., 2017). The mated gynes perform short-range dispersal on the ground or more rarely a wider dispersal on the wing. As a minimalistic colony founding strategy, an uninseminated gyne taking along some workers can establish a normal colony by mating with the first male, developing from her own haploid eggs (Frohschammer, 2015) (Seifert, 2022).

Identification
Worker (Figure 12, pictures CASENT0280593 in www.antweb.org; Table 2): Largest species of the C. argentea group, CS 512 µm. Compared to C. argentea n.sp., head much more elongated (CL/CW 1.133) but postocular distance smaller (PoOc/CL 0.408). Scape longer than in any related species, SL/CS 0.859. Eye small, EYE 0.216. In position with CL in visual plane, anterior clypeal margin between the level of frontal carinae straight to slightly concave and occipital margin straight or very slightly concave. Frontal carinae wide, slightly converging immediately posterior of the FRS level, FRS/CS 0.302. Mesosoma thickset and short; its length without neck shield only 1.1 of CL. Dorsal profile of mesosoma hump-backed, strongly and evenly convex, without any metanotal groove. Spines rather long (SP/CS 0.267), acute, their axis in lateral view deviating by 30° from longitudinal axis of mesosoma, spine bases widely distant, SPBA/CS 0.369. Petiole in lateral view high (PeH/CS 0.336), with a short peduncle, a concave frontal and convex caudodorsal profile; the node in dorsal view wider than long, PeW/CS 0.303. Postpetiole in dorsal view narrow (PpW/CS 0.423), extremely short and with a straight or slightly concave anterior margin; in lateral view very low (PpH/CS 0.252), with a semicircular ventral profile that is produced by prominent bilateral lobes of the sternite which strongly protrude compared to median level (Figure 12D). Whole surface of head and mesosoma densely foveolate-reticulate, thus appearing at lower magnifications perfectly matt. Foveolae on vertex or dorsal mesosoma badly visible due to superimposed pubescence and disguising inner structure that is reminiscent of a tree- or four-leafed clover leaf, foveolar diameter on vertex 11–15 µm. Petiole and postpetiole foveolate-microreticulate and matt. First gaster tergite shiny, with a delicate, fragmentary microreticulum. Cephalic and mesosomal pubescence hairs flattened and appearing silvery, their larger diameter about 4 µm, the smaller one about 2.5 µm. Gastral pubescence not flatted, rather long and dense (PLG/CS 6.05%, sqPDG 3.99). Whole body rather concolorous dark to medium brown.

For separation from the closely related species Cardiocondyla argentea and Cardiocondyla semiargentea, see C. argentea.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Malaysia, Philippines.

Nomenclature

 * . Cardiocondyla argyrotricha Seifert, 2022: 40, fig. 12 (w.) MALAYSIA.

Type Material
Holotype worker plus three paratype workers labelled “MAL: 1.7294° N, 110.4472° E, Baku NP Strand, 0 m, Frohschammer 2007.05.24–16”; four paratype workers labelled “MAL: 1.7294° N, 110.4472° E, Baku NP Strand, 0 m, in Stein, Frohschammer 2007.05.24-18”; four paratype workers labelled “MAL: 1.7294° N, 110.4472° E, Baku NP Strand, 0 m, in Stein, Frohschammer 2007.05.24-19”; all deposited in SMN Görlitz.