Cardiocondyla tibetana

Seifert (2023) reports two nests were found by Roland Schultz in a semidesert zone in an area with clay or loamy soil occasionally flooded by the river Tarim and covered by light tamarisk stands.

Identification
Seifert (2003) - A member of the Cardiocondyla stambuloffii group. The unique character combination of Cardiocondyla tibetana enables a safe distinction from any known Palaearctic species both by morphometry, body shape, and microstructures. The minute hair base punctures and full absence of any foveolae on the vertex, as well as the shape of the spines and postpetiole are the reasons for positioning C. tibetana near the Cardiocondyla stambuloffii group. However, the larger eye size, the narrower frons, the lower petiole height and postpetiole width indicate affinities to both the Cardiocondyla elegans and the Cardiocondyla bulgarica groups.

Seifert (2023) - Rather small, CS 540 µm. Head short, CL/CW 1.159. Postocular index smaller than in other members of the stambuloffii group, PoOc/CL 0.424. Hind margin of head with a suggested concavity in the median third. Scape longer than in other members of the stambuloffii group, SL/CS 0.838. Eye larger than in other members of the stambuloffii group, EYE/CS 0.248. Frons narrower than in other members of the stambuloffii group (FRS/CS 0.280), frontal carinae weakly converging immediately caudal of FRS level (FL/FR 1.047). Dorsal profile of promesonotum convex, metanotal depression rather shallow (Mgr/CS 3.14 %), dorsal profile of propodeum slightly convex. Propodeal spines reduced to obtuse angled corners, SP/CS 0.044), the distance of their bases much smaller than in other members of the stambuloffii group (SPBA/CS 0.219). Petiole more than half as wide as postpetiole and distinctly higher than wide (PeW/CS 0.271, PeH/CS 0.310), in profile with a moderately short peduncle and the anterior slope of the node much less inclined than the posterior slope (58° vs. 71° relative to ventral petiole profile)—as result the node profile is strongly asymmetric. Petiole node in dorsal view wider than long. Postpetiole much narrower and lower than in other members of the stambuloffii group and less than twice as wide as high (PpW/CS 0.510, PpH/CS 0.265), in dorsal aspect with a rather straight anterior margin, postpetiolar sternite completely flat. Clypeus, frontal laminae, and anterior 70% of median and paramedian vertex very densely longitudinally carinulaterugulose; distance between carinulae on central vertex only 4–5 µm. Carinulae on lateral vertex interrupted and with much larger, more or less shining interspaces. Poorly visible hair base punctures of only 5–7 µm diameter are scattered in the interspaces; many of the hair bases without surrounding micropunctures (Fig. 104). Posterior third of head almost glabrous, only scattered hair base punctures present. Foveolae of any size and type on whole head completely absent. Pronotum glabrous. Dorsal parts of mesonotum and propodeum mainly smooth and shining, longitudinal carinulae may be present. Lateral mesonotum with interrupted, meso- and metapleurae with stronger, more continuous longitudinal rugulosity. Petiole and postpetiole smooth and shiny. Pubescence on gaster tergites moderately long and dense, PLg/CS 6.39 %, sqPDg 3.54. Whole body rather concolorous medium to blackish brown, appendages and sometimes clypeus lighter with yellowish tinge.

The character combination of Cardiocondyla tibetana is unique and enables a safe distinction from any known Palaearctic species both by morphometry, body shape, and microstructures. The minute or absent hair base punctures and full absence of any foveolae on vertex, as well as spine and postpetiolar shape were the reasons for placing C. tibetana in the stambuloffii group. However, the larger eye size, the narrower frons, and the lower petiole height and postpetiole width also indicate affinities to the elegans or ulianini groups.

Distribution
Seifert (2023) - Three findings with precise site records are at the southern and northern margin of the Taklamakan desert (37.015°N, 80.729°E, 1366 m; 41.175°N, 84.232°N, 920 m). The precise locality of gustav Mayr’s sample is unclear but probably at the margin of the Tarim Basin with the Tibetan Plain.

Distribution based on Regional Taxon Lists
Oriental Region: Tibet. Palaearctic Region: China.

Nomenclature

 * . Cardiocondyla tibetana Seifert, 2003a: 269, fig. 49 (w.) CHINA (Tibet).
 * Type-material: holotype worker, 2 paratype workers.
 * Type-locality: holotype China: Tibet, S Takklamakan Desert, 36.52°N, 81.41°E, Cele Research Station, 26.viii.1996 (no collector’s name); paratypes: 2 workers China: Tibet (no further data).
 * Type-depositories: SMNG (holotype); NHMW (paratypes).
 * Status as species: Guénard & Dunn, 2012: 41.
 * Distribution: China.

Type Material

 * Holotype worker (the specimen with CW = 510) and 2 paratype workers labelled “S Takklamakan Desert: 81.41 E, 36.52 N, Cele Research Station, 1996.08.26”,
 * 2 paratype workers pierced on minute pins in the same block of Sambucus pith and labelled “Tibet coll. G.Mayr”,

Worker
Head moderately elongated, CL/CW 1.161. Scape longer, frons narrower, and eye distinctly larger than in members of C. stambuloffii group; SLiCS 0. 849, FRS/CS 0.284, EYE 0.250. Postocular distance shorter than in Cardiocondyla gibbosa, PoOc/CL 0.424. Clypeus, frontal laminae, median and paramedian vertex very densely longitudinally carinulate-rugulose; distance between carinulae on central vertexonly 4 - 5 mm. Carinulae on lateral area of vertex interrupted and with much larger, more or less shining interspaces. Poorly visible hair base punctures of only 5 - 8 mm diameter scattered in the interspaces; many of hair bases without surrounding micropunctures (Fig. 49 shows no average situation). Foveolae completely absent. Posterior third of head almost glabrous, only scattered hair base punctures present. Pronotum glabrous. Dorsal parts of mesonotum and propodeum mainly smooth and shining, longitudinal carinulae may occur. Mesonotum laterally with interrupted, meso- and metapleurae with stronger, more continuous longitudinal rugulosity. Propodeal spines reduced to very short dents. Petiole much lower and postpetiole much narrower than in members of C. stambuloffii group, PEH/CS 0.3 1 6, PPW/CS 0.502. Petiole node wider than long. Whole body rather concolorous medium to blackish brown, appendages and sometimes clypeus lighter with yellowish tinge.

References based on Global Ant Biodiversity Informatics

 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Seifert B. 2003. The ant genus Cardiocondyla (Insecta: Hymenoptera: Formicidae) - a taxonomic revision of the C. elegans, C. bulgarica, C. batesii, C. nuda, C. shuckardi, C. stambuloffii, C. wroughtonii, C. emeryi, and C. minutior species groups. Annalen des Naturhistorischen Museums in Wien. B, Botanik, Zoologie 104: 203-338.