Tapinoma breve Emery 1925

Seifert, Bernhard, Kaufmann, Bernard & Fraysse, Lorenzo, 2024, A taxonomic revision of the Palaearctic species of the ant genus Tapinoma Mayr 1861 (Hymenoptera: Formicidae), Zootaxa 5435 (1), pp. 1-74 : 37

Tapinoma breve Emery 1925 , syn. nov. [type investigation]

The taxon has been described based on material collected by Kuznetzov-Ugamsky in the Kysyl valley, former Syr Darja province, at an elevation of 6000 feet. According to the altitude record, the site must be in the NW Tian Shan (approximately at 42.5°N, 71.6°E) and belongs to the present Kyrgistan. Investigated were two syntype workers from MCSN Genova, labelled “Prov. Syr Darja, Kisil Tal”, “ T. breve Emery ”[Emery’s handwriting], “ANTWEB CASENT0904020”, “ SYNTYPUS Tapinoma breve Emery, 1925 ”. The specimen CASENT0904020 with CW=644 is fixed by present designation as lectotype. The other type specimen has CW= 563. The type sample is allocated to the T. glabrella cluster with p= 0.9446 in a wild-card run of a LDA considering 12 morphometric characters ( Tab. 1) .

Material examined. Numeric phenotypical data were taken in 70 samples (largely nest samples) with 219 workers. They originated from Albania (3 samples), Bulgaria (8), Croatia (9), France (1), Georgia (2), Greece (3), Iran (3), Italy (6), Kazakhstan (2), Kyrgistan (17), Montenegro (4), Slovenija (3), Turkey (7) and Ukraine (2). For details see supplementary information SI1, SI2 .

Geographic range. Widely distributed over the Mediterranean, Submediterranean, Ponto-South-Siberian and Turanian regions of the West and Central Palaearctic. The western, eastern, southern and northern range limits are at 3.9°E in France , at 82.3°E in Kazakhstan , at 33.2°N in Central Iran and at 49.4°N in the Ukraine . Ascending to 2500 m at 38.5°N in Turkey . Broadly sympatric with T. erraticum in Italy and the W Balkans and there is a small sympatric zone with T. israelis in Asia Minor.

Diagnosis:—Worker ( Tab. 2): All shape ratios given below are, in contrast to those in Tab. 2, primary ratios without RAV and all data are given as arithmetic mean ± standard deviation. Slightly larger than erraticum, CS 777 ± 83 µm. Head moderately elongated CL/CW 1.124 ± 0.046. Postocular distance medium-sized, PoOc/CL 0.405 ± 0.011. Anteromedian clypeal excision slightly deeper and narrower than in erraticum, ExCly /CS 9.07 ± 1.53 %, ExClyW 5.84 ± 0.70 %. The margin of clypeal excision forms a sharp cuticular edge beginning from its frontal corners caudad over at least 70% of its length and is in this area at same level as the adjacent clypeal surface. Sum of pubescence hairs and smaller setae protruding at a few micron across margin of clypeal excision larger than in erraticum , nExCly 4.87 ± 3.50. Posterior margin of head in full face view in medium-sized and large specimens slightly excavated, ExOcc/CS 1.17 ± 0.77 %. Scape shorter than in erraticum, SL /CS 0.987 ± 0.025. Minimum distance of the inner margins of antennal socket rings medium-sized, dAN/CS 0.285 ± 0.008. Eye slightly larger than in erraticum, EL /CS 0.271 ± 0.009. Metanotal groove moderately deep, MGr/CS 3.12 ± 1.03 %. Mesosoma slightly narrower and shorter than in erraticum, MW /CS 0.648 ± 0.023, ML/CS 1.324 ± 0.035. Second funiculus segment shorter than in erraticum, Fu 2L/CS 13.41 ± 0.40 %, IFu2 1.579 ± 0.083. Seta condition, pubescence and pigmentation similar to T. erraticum .

—Male genital (Fig. 02): Ventral aspect. In basic structure similar to erraticum and showing a lot of variation which prevents a clear species separation by simple eye inspection. Lobes of subgenital plate rather broad, their length extends over 50 to 90% of the visible length of the basimere. The apical margins of the lobes vary from straight to semicircular. The shape of the mediodistal part of the basimere shows various transitions between three extremes: (1) it may form a sharp hook the tip of which is directed mediad, (2) it is straight and directed mediocaudad and shows a rather blunt chisel-like tip, (3) it forms a sharp spine-like extension directed caudad. The harpago segments are rather small, their lateral margins are usually more strongly incurved towards the tip than in erraticum .

Taxonomic comments. The clear separation of workers from Tapinoma erraticum and T. israelis was shown in the section on Tapinoma erraticum . In contrast to the rather monomorphic situation in T. erraticum , the T. glabrella worker population shows a high variation due to significant geographic substructuring within its huge range. This is mirrored by the situation in male genitalia. Reasons for the synonymization of Tapinoma tauridis Emery 1925 and Tapinoma breve Emery 1925 based on investigation of type specimens are given in the explanatory text within the account of synonymies.

Biology. Among 27 records with information on habitat, 25 referred to open land and 2 to light broad-leafed forest. Within the open land habitats, pastures and uncultivated dry grasslands dominated but the list included also rural and urban habitats such as road sides, gardens or city parks. Furthermore, it occurred on gravel banks of floodplains, here occasionally in rather moist conditions, and one nest was found in a moving aeolic sand dune. Nests were polygynous and the main period for occurrence of alates was 3 May to 6 June.