Cardiocondyla elegans var. sahlbergi Forel 1913

Seifert, Bernhard, 2023, A revision of the Palaearctic species of the ant genus Cardiocondyla Emery 1869 (Hymenoptera: Formicidae), Zootaxa 5274 (1), pp. 1-64 : 38-39

Cardiocondyla elegans var. sahlbergi Forel 1913 [type investigation]

This taxon has been described from eastern Caucasus. Investigated was the lectotype gyne labelled “ C.elegans var. sahlbergi Forel , $ type, Caucase (Ruszky) ” and on a second label “ Aralokaspigebiet ”, MHN Genève. If both labels are true, the terra typica should be the eastern Caucasus (present Dagestan or Azerbaijan). Three worker paratypes, placed in the box with the lectotype gyne of C. sahlbergi and with similar labelling by Forel (“ C.elegans var. sahlbergi Forel , type, Caucase (Ruszky) / Aralokaspigebiet”) do not belong to C. sahlbergi and are instead typical C. ulianini in both structure and morphometry.

All material examined. Numeric phenotypical data were available in 39 samples (largely nest samples) with 77 workers. For details see supplementary information SI1, SI2. This material originated from Afghanistan (1 sample) , Azerbaijan (1) , Georgia (9), Iran (10), Israel (1), Kazakhstan (1), Kyrgystan (1), Russia (3), “Turkestan” (2), and Turkey (8).

Geographic range. Touches Europe by the westernmost site at Altunkent (41.01°N, 28.67°E). Distributed eastwards over Asia Minor , the Great Caucasus, the Caspian region , the Iran , and Afghanistan to Kyrgistan (42.9°N, 74.6°E). The southernmost sites are in the Iran (29.59°N, 51.99°E) and in Israel (32.95°N, 35.63°E) . The altitudinal range varies from minus 29 m in the Caspian region to 2000 m at the southernmost site in the Iran .

Diagnosis: --Worker ( Tab. 2 , Figs. 46–49 , key; pictures CASENT0908341 (paralectotype sahlbergi ), CASENT0917364 (wrong neotype des. Radchenko of Cardiocondyla bogdanovi , see p. 48 C. stambuloffii ) in www.antweb.org). Medium-sized, CS 522 µm. Head moderately elongated, CL/CW 1.176. Postocular distance large, PoOc/CL 0.439. Scape moderately elongated, SL/CS 0.798. Eye rather small, EYE/CS 0.231, with notable microsetae. Occipital margin weakly concave. Frons rather broad (FRS/CS 0.256), frontal carinae slightly converging immediately caudal of FRS level (FL/FR 1.058). Dorsal profile of promesonotum and of propodeum convex with a rather deep metanotal depression (MGr/CS 3.83 %). Spines rather short and acute (SP/CS 0.125), their axis in profile deviating by about 35° from longitudinal axis of mesosoma, their bases rather distant (SPBA/CS 0.279). Petiole rather wide and slightly higher than wide (PeW/CS 0.331, PeH/CS 0.351); in profile with a rather long peduncle and moderately steep anterior and posterior slopes of the node (about 65° and 62° relative to ventral profile—i.e. rather symmetric). Postpetiole wide and moderately high (PpW/CS 0.565, PpH/CS 0.305), in dorsal view suggestively heard-shaped, with a concave anterior margin and convex sides. Head in overall impression shiny. Whole vertex with shallow, feebly bicoronate foveolae of 16–18 µm diameter, foveolar distance on central vertex larger than foveolar diameter, near to eyes about equal to foveolar diameter, the interspaces very shiny and with very delicate stickman-like microstructures ( Fig. 49 ). Mesosoma shiny, microreticulum and microrugulae very weakly developed, a few foveolae are present on dorsal promesonotum. Waist segments very shiny with barely visible microreticulum. Pubescence on whole body rather short and dilute, PLG/CS 6.4 %, sqPDG 4.64. Color of head, mesosoma, waist and gaster usually homogenously dark brown; mandibles, scape, tibiae and tarsae pale yellowish brown.

Taxonomic comments and clustering results. In his original description of C. sahlbergi, Forel explicitly referred only to a gyne from “ Palestine (Sahlberg)” and a gyne from “Caucase (Ruzsky)”. The first specimen could not be discovered during a search in the collections of Forel in Lausanne, Genève, and Basel but the latter gyne is present in the MHN Genève collection under the labelling “ C.elegans Em. v. sahlbergi type For., Caucase (Ruszky)”, “Aralokaspigebiet N2”, “Typus” [printed red label] and “ANTWEB CASENT 098340”. This specimen was fixed by Seifert (2003) as lectotype. A worker specimen with the same labelling but “ANTWEB CASENT 098341” was not directly investigated but is in any character shown by the images in www.antweb.org consistent with the worker concept of C. sahlbergi presented here. The gynes of C. sahlbergi , C. persiana and C. bulgarica are separated by a PCA of the characters CS, CL/CW, PoOc/CL, SL/CS, PeW/CS, PpW/CS, SP/CS, sqPDG, PLG/CS, PeH/CS, PpH/CS, dFOV, ML/CS with the type specimens being allocated to their corresponding clusters ( Fig. 138 ). This is in agreement with the clustering of workers.

The workers of C. sahlbergi are similar to those of C. persiana but differ from the latter by shorter microsetae on clypeus (compare Figs. 46 and 50 ), shorter pubescence on all body parts, smaller, less densely packed vertex foveolae (compare Figs. 49 and 53 ), wider waist segments, the petiole node in lateral view being more symmetric (compare Figs. 47 and 51 ) and a frequently darker mesosoma. A character-reduced LDA using the characters CS, SL/CS, PeW/CS, sqPDG, dFOV, PigCon, EYE/CS classifies 99.0 % of 103 worker individuals of both species correctly and provides a strong separation on the nest sample level ( Fig. 139 ).

Biology. Unknown.

Figures

FIGURE 138. Separation of gyne individuals of Cardiocondyla persiana (black triangle, n=1), C. sahlbergi (white dots, n=13) and C. bulgarica (black rhombs, n=10) by a principal component analysis considering the morphometric characters CS, CL/ CW, PoOc/CL, SL/CS, PeW/CS, PpW/CS, SP/CS, sqPDG, PLG/CS, PeH/CS, PpH/CS, dFOV, ML/CS. The type specimens are marked by a “T”.

FIGURE 139. Separation of nest samples of Cardiocondyla sahlbergi (white dots, n=38) and C. persiana (black triangles, n=10) by a linear discriminant and a principal component analysis considering the morphometric characters CS, SL/CS, PeW/ CS, sqPDG, dFOV, PigCon, EYE/CS.

FIGURES 46–49. Cardiocondyla sahlbergi; Fig. 46: head in dorsal view; Fig. 47: lateral view; Fig. 48: dorsal view; Fig. 49: head surface between inner eye margin and paramedian vertex. Russia: Barkhan Sarykum, 2017.04.21

FIGURES 50–53. Cardiocondyla persiana, paratype; Fig. 50: head in dorsal view; Fig. 51: lateral view; Fig. 52: dorsal view; Fig. 53: head surface between inner eye margin and paramedian vertex. Iran: Shiraz-7 km NE, 1997.09.18