Cardiocondyla rugulosa

Known only from the holotype worker from Yemen, nothing is known about the biology of .

Identification
Seifert (2003) - A member of the Cardiocondyla batesii group. Cardiocondyla rugulosa is morphometrically similar to Cardiocondyla nigra. The highly diagnostic character of C. rugulosa is the presence of strongly developed longitudinal rugulae or carinulae on the vertex, which are much denser than in any related species. By the much denser and stronger sculpture the surface of head, mesosoma and petiole appears mat. The shallower metanotal groove and the more massive waist segments (with larger PEH/CS, PPH/CS, and PP/CS) provide additional criteria for separation from C. nigra.

Seifert (2023) - Rather large, CS 576 µm. Head moderately elongated, CL/CW 1.168. Postocular index low, PoOc/CL 0.344. Median third of hind margin of head notably concave. Scape rather short, SL/CS 0.789. Eye large, EYE/CS 0.267. Frons moderately broad (FRS/CS 0.249), frontal carinae slightly converging immediately caudal of FRS level (FL/FR 1.027). Mesosoma in lateral view characteristic: dorsal profile of promesonotum only weakly convex, metanotal depression shallow (Mgr/CS 2.1 %) and dorsal profile of propodeum more strongly convex and more strongly sloping down to spine base than in related species. Spines short (SP/CS 0.101), acute and weakly erected, their axis in profile deviating by about 33° from longitudinal axis of mesosoma, their bases more approached (SPBA/CS 0.240). Petiole distinctly higher than wide (PeW/CS 0.276, PeH/CS 0.329), in profile with a short peduncle, a rather straight to weakly convex anterior face and an ample node with the anterior slope less steep than the caudal slope, petiole in dorsal view with elongated node that gradually merges with the anterior peduncle. Postpetiole wide (PpW/CS 0.537, PpW /PeW 1.95, PpH/CS 0.286), in dorsal view suggestively heard-shaped, with a concave anterior margin and convex sides; postpetiolar sternite completely flat. Clypeus and frontal laminae finely longitudinally rugulose. Whole vertex densely and finely longitudinally rugulose, the numerous foveolae of 14–18 µm diameter are not eye-catching because of being embedded within the rugosity, foveolar interspaces on paramedian vertex about as wide as foveolar diameter and glabrous (Fig.69). Dorsal promesonotum with scattered foveolae and weakly microreticulate between superimposed longitudinal rugulae. Propodeum irregularly microreticulate. Lateral pronotum moderately shiny but on whole surface microreticulate. Lateral mesonotum and mesopleuron reticulate and longitudinally rugulose. Lateral metapleuron with 5–7 weak, longitudinal carinae. Petiole irregularly microreticulate. Postpetiole more shiny, with very delicate microreticulum. Pubescence on gaster tergites moderately long and moderately dense, PLg/CS 5.41 %, sqPDg 5.48. Head, gaster, femora, and tibiae dark brown to blackish brown. Mesosoma and postpetiole dark brown with reddish component. Petiole orange brown.

C. rugulosa is morphometrically similar to Cardiocondyla nigra. The most diagnostic character of C. rugulosa is the strong longitudinal rugulae or carinulae on whole surface of dorsal head. The much more dense and stronger sculpture produces a mat surface appearance on head, mesosoma and petiole. The mesosomal shape is also characteristic: a feebly convex dorsal profile of promesonotum is contrasted by the more strongly convex dorsal profile of propodeum which is more strongly sloping down to spine base than in related species.

Distribution
So far only known from the type locality, Sana’a, Yemen (15.37°N, 44.19°E, 2265 m) (Seifert, 2023).

Distribution based on Regional Taxon Lists
Afrotropical Region: Yemen.

Nomenclature

 * . Cardiocondyla rugulosa Seifert, 2003a: 244, fig. 25 (w.) YEMEN.
 * Type-material: holotype worker.
 * Type-locality: Yemen: Sana’a, v.1991 (A. van Harten).
 * Type-depository: SMNG.
 * Status as species: Borowiec, L. 2014: 48.
 * Distribution: Yemen.

Worker
Scape rather short, SL/CS 0.789. Postocular distance smaller than in related species, PoOc/CL 0.344. Occipital margin notably excavated. Eyes large, EYE 0.267. Clypeus and frontal laminae finely longitudinally rugulose. Frontal carinae immediately posterior of FRS level parallel. Whole vertex densely and finely longitudinally rugulose. Foveolae of 14 - 18 mm diameter present on paramedian vertex, barely visible and embedded within rugulae (Fig. 25). Dorsal area of promesonotum with scattered foveolae, and weakly microreticulate between superimposed longitudinal rugulae. Propodeum and petiole irregularly microreticulate. Postpetiole more shining, with very delicate microreticulum. Pronotum laterally moderately shining and microreticulate. Lateral areas of mesonotum and mesopleuron reticulate and longitudinally rugulose. Metapleuron laterally with 5 - 7 weak, longitudinal carinae. Metanotal groove rather shallow. Spines steep, short and acute. Petiole node in dorsal and lateral aspect similar to Cardiocondyla batesii but more massive. Postpetiolar sternte without any flat bulge. Head, gaster, femora, and tibiae dark brown to blackish brown. Mesosoma and postpetiole dark brown with reddish component. Petiole light-orange brown.

Type Material
Holotype worker labelled “Yemen, Sana'a, 1991.05, leg. A. van Harten”,.