Lasius cinereus Seifert 1992

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 : 68-69

4.4.36 Lasius cinereus Seifert 1992

Lasius cinereus Seifert 1992 [type investigation]

Type material: Holotype plus 2 paratypes on the same pin labelled ” 45 km N Castellon 7.5.91,- 116, 430 m 5 WSW Alcala de Chivert“; depository: SMN Görlitz.

All material examined. A total of 20 nest samples with 58 workers were subject to NUMOBAT investigation. These originated from France (3) and Spain (17). For details see supplementary information SI1.

Geographic range. Iberia and southernmost France with the northern border running here approximately over points near Montpellier (43.63°N, 3.87°E), near Avignon (43.97°N, 4.60°E) and near Cannes (43.51°N, 6.91°E). Altitudinal records range from 70–200 m in southern France and 430–1950 m in Spain.

Diagnosis ( Tab. 7 , Figs. 69 –70; key; images in www. AntWeb.org with specimen identifiers FOCOL0743):

A species related to L. grandis . Absolute size rather small (CS 860 µm). Head and scape length indices large (CL/CW 900 1.091, SL/CS 900 1.012); postocular distance low (PoOc/CL 900 0.219); torulo-clypeal distance large (dClAn 900 5.01); eye size rather small (EYE/CS 900 0.233); terminal segment of maxillary palp moderately long (MP6/CS 900 0.197). Number of mandibular dents large (MaDe 900 8.69). Pubescence on clypeus rather dense (sqPDCL 900 4.37); frontal pubescence very short (PLF 900 23.5). All body parts with rather numerous standing setae of medium length (PnHL/CS 900 0.146, GuHL/ CS 900 0.116, nGu 900 13.2, nSc 900 22.6, nHT 900 20.1). In difference to L. grandis , cuticular surface of dorsal head and mesosoma completely matt; this is caused by fine punctures (”ultrastructures“) within the meshes of the microreticulum or in interspaces of microrugae. Coloration: head and gaster blackish brown; mesosoma dark to medium brown with a yellowish-reddish tinge but even in the lightest specimens darker than in the light color morph of L. emarginatus . Mandibles, anterior clypeal margin and scape orange brown.

Biology. The majority of the sites are on limestone ground with habitats including xerothermous grassland, bare rocky ground with spiny shrubs, a sunny Juniperus-Artemisia phytoassociation, open broad-leafed forest or sunny Pinus forests. L. cinereus is distinctly more xerothermous than L. grandis and there seems to exist mutual spatial exclusion. Nest were under stones, in dead wood laying on ground, and in soil. The workers behave aggressively during disturbance of the nest.

Comments. Apart from the frequently diagnostic ultrastructure of cuticular surface, 46 nest samples of Lasius cinereus and L. grandis with the full set of standard NUMOBAT data available were separated by any of the four variants of NC-clustering with an error rate of 0%. The classification error by an LDA was 0.7% in 134 worker individuals of both species.

Figures

Figs. 69 and 70: Lasius cinereus; holotype