Lasius niger (Linnaeus 1758)

Seifert, Bernhard, 2020, A taxonomic revision of the Palaearctic members of the subgenus Lasius s. str. (Hymenoptera, Formicidae), Soil Organisms 92 (1), pp. 15-86 : 63

4.4.25 Lasius niger (Linnaeus 1758)

Formica nigra Linnaeus 1758 [type investigation]

Type material: Neotype worker plus 2 workers from the neotype nest labelled ”S:B1. Johannishus 1 km NE k:a, RN-03F6f03, 10.08.74, P. Douwes DATA ZOOTAX“; depository ZMLU Lund.

All material examined. A total of 131 nest samples with 281 workers were subject to NUMOBAT investigation. These originated from Algeria (1 sample), Bulgaria (1), Czechia (14), Denmark (2), England (3), Finland (1), France (6), Germany (43), Italy (2), Kazakhstan (10), Kyrgyzstan (7), Mongolia (2), Poland (3), Portugal (1), Russia (15), Slovakia (6), Spain (4), Sweden (8), Turkey (1). For details see supplementary information S1.

Geographic range. Eurosiberian. Originally it was probably a species of the northern steppe zone and the transition zone from steppe to temperate forest but following the spread of human culture there was a strong range expansion even into the Mediterranean and S boreal zone. Total range from W Europe (10°W) to S Baikal region (108°E); going north to 63.6°N along the coast of Norway and to 64.5°N along the Gulf of Bothnia. Due to confusion with Lasius grandis , distribution in the Mediterranean region very poorly known, here probably rare and mainly above 700 m but occasionally found in humid coastal lowland habitats and even the town of Alger (here introduced?). In Central Europe planar to subalpine, in the Alps (Vorarlberg) up to 1900 m, in the Tian Shan at 42°N ascending to 2250 m. In SW Siberia a typical and abundant element of humid steppe, of river valleys, and cities.

Diagnosis ( Tab. 6 , Figs. 49 –50; key; images in www. AntWeb.org with specimen identifiers CASENT0178773, CASENT0179897, CASENT0179929):

Absolute size rather large (CS 976 µm). Head, scape and maxillary palp length indices, postocular distance and eye size medium (CL/CW 900 1.074, SL/CS 900 0.979, MP6/CS 900 0.180, PoOc/CL 900 0.235, EYE/CS 900 0.245). Number of mandibular dents medium (MaDe 900 8.26). Pubescence on clypeus very dense (sqPDCL 900 3.58). All body parts with numerous standing setae but the length of setae is low (PnHL/CS 900 0.123, GuHL/CS 900 0.094). Coloration: Head, gaster, petiole, coxae, femora and tibiae dark brown; mesosoma dark brown to medium brown with a slight yellowish tinge; mandibles, scape, trochanter and tibio-femoral joint region yellowish-reddish brown.

Biology. See Seifert (2018).

Comments. Lasius niger is an unmistakable combination of very dense clypeal pubescence, numerous setae on all body parts but rather short setae length. It is safely separated from any Palaearctic species by different algorithms of NC-clustering. For separation from Lasius vostochni sp. nov. see below.

Figures

Figs. 49 and 50: Lasius niger; CASENT0179897, photo E. Prado