Cardiocondyla elegans var. dalmatica Soudek 1925

Seifert, Bernhard, 2023, A revision of the Palaearctic species of the ant genus Cardiocondyla Emery 1869 (Hymenoptera: Formicidae), Zootaxa 5274 (1), pp. 1-64 : 29-30

Cardiocondyla elegans var. dalmatica Soudek 1925 [type investigation]

This taxon has been described from the Gulf of Kotor / Montenegro. Investigated was one worker from NHM Basel, labelled “Boka Kotorska, Dalmacia, 1923, Dr. Soudek ” and one worker from ZIPAS Warszawa labelled “Boka Kotor, Igalo VII 1922, Dr.Soudek ”. Both specimens are most similar in morphology and are allocated to the dalmatica cluster in a wild-card run of the LDA mentioned above with p = 1.0000 (specimen from “Boka Kotorska”) and p = 0.9961 (specimen from “Boka Kotor, Igalo”). The original description of Soudek (1925) does not give collecting dates and only reports of a single colony found “at Erceg Novi (Castelnuovo) in the Gulf of Kotor”. As the locality Igalo is a part of the town Herceg Novi, the specimen from this locality is better attributable to Soudek’s statements and is fixed herewith as lectotype .

All material examined. Numeric phenotypical data were available in 32 samples (largely nest samples) with 72 workers. For details see supplementary information SI1, SI2. This material originated from Albania (1 sample), Bulgaria (5), Cyprus (1), Greece (15), Hungary (2), Iran (1), Italy (1); Montenegro (2) and Turkey (4).

Geographic range. From N Italy (8.6°E), across the whole Balkans, Cyprus and Asia Minor east to the Iran (52.7°E). The northern range border is demarcated by 47. 78°N and 16.84°E in Austria ( Zettel et al. 2021), 47.83°N 18.83°E in Slovakia ( Bezdecka & Tetal 2013) and 48.07°N, 19.29°E in Hungary. All European sites are below 600 m but in the Iran it ascends to 1700 m (29.76°N, 52.70°E). The mean air temperature May–Aug of 29 sites is 22.23 ± 2.12 [18.7, 25.8] °C.

Diagnosis: --Worker ( Tab. 1 , Figs. 10–13 , key; pictures CASENT0179878,ANTWEB 1041351 in www.antweb.org). Relatively large, CS 554 µm. Head moderately elongated, CL/CW 1.156. Postocular distance low, PoOc/CL 0.399. Scape long, SL/CS 0.855. Eye rather large, EYE/CS 0.247, with notable microsetae. Occipital margin suggestively concave to straight. Frons rather broad (FRS/CS 0.258), frontal carinae slightly converging immediately caudal of FRS level (FL/FR 1.045). Dorsal profile of promesonotum and of propodeum convex with a rather deep metanotal depression (MGr/CS 3.90 %). Spines rather short and acute (SP/CS 0.109), their axis in profile deviating by about 35° from longitudinal axis of mesosoma, their bases rather distant (SPBA/CS 0.262). Petiole narrower than in C. elegans and slightly higher than wide (PeW/CS 0.313, PeH/CS 0.329); in profile with a moderately long peduncle and a steep anterior slope of the node (about 65° relative to ventral profile). Postpetiole rather wide and moderately high (PpW/CS 0.562, PpH/CS 0.298), in dorsal view suggestively heard-shaped, with a concave anterior margin and convex sides; postpetiolar sternite convex. Head in overall impression mildly shiny. Whole vertex with shallow, feebly bicoronate foveolae of 16–18 µm diameter, foveolar distance on paramedian vertex smaller than foveolar diameter, near to eyes larger; the interspaces between foveolae shiny and in places with fragments of a very delicate microreticulum ( Fig. 13 ). Mesosoma shiny, with weakly developed microreticulum and microrugulae, a large number of foveolae present on dorsal promesonotum, their distance approximately equal to their diameter. Dorsal propodeum glabrous but with small foveolae and a very delicate microrugosity. Dorsum of waist glabrous, with scattered fragments of very fine microreticular structures. First gaster tergite glabrous. Pubescence on whole body long and dense, PLG/CS 7.57 %, sqPDG 4.09. Color of head, mesosoma, waist and gaster usually homogenously dark to medium brown; mandibles, scape, tibiae and tarsae yellowish brown.

Taxonomic comments and clustering results. Cardiocondyla dalmatica is an eastern, parapatric sibling species of C. elegans with a sympatric occurrence, as far as known, only in N Italy. Both species are in basic shape and surface structure extremely similar but there are significant differences in PeW, SL, MGr and PpW ( Tab1 .). The clear separation of both species by exploratory and hypothesis-driven data analyses is reported in the previous section (p. 29).

Biology. A strongly thermophilous species. Natural habitats are open riverine or coastal sand-gravel banks, dunes and solonchaks with very sparse herb layer. There is a considerable habitat shift to anthropogenous sites; it is frequent here at roadsides, country lanes, camping grounds etc. The simple soil nests usually show a single, very narrow entrance hole of 1.0– 1.4 mm diameter which leads to a vertical duct that passes through a number of chambers down to 50 cm in habitats with low water table. A nest entrance in the solonchaks at Lake Neusiedlersee, situated within a transitional zone which is flooded for several days to weeks annually, was according to Zettel et al. (2021) only 15 cm above the water table. The material around this entrance was strongly cemented and the entrance could be closed when flooded. One nest excavated in Bulgaria contained 150 workers, 7 ergatoid males, 155 alate gynes and one queen and the nests are probably monogynous at the nest level. Mating and colony foundation is probably as in C. elegans ( Seifert 2018) . Gynes are polymorphic in mesosoma size and wing length—flight dispersal and independent colony foundation is supposed for macrosomatic-macropterous gynes in particular. Forages at surface temperatures up to 50°C on soil surface and in the lower herb layer. Apparently largely zoophagous. Visits nectaries. It behaves submissive and cryptic in respect to other ants.

Figures

FIGURES 10–13. Cardiocondyla dalmatica, Fig. 10: head in dorsal view; Fig. 11: lateral view; Fig. 12: dorsal view; Fig. 13: head surface between inner eye margin and paramedian vertex. Hungary: Balassagyarmat, 2007.06.31