Lasius longipalpus, Seifert, 2020

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 : 77-78

4.4.53 Lasius longipalpus sp. nov.

Etymology. The name refers to the terminal segment of maxillary palps which is long compared to sympatric smaller-sized and weakly-haired species.

Type material. Holotype and 2 paratype workers on one pin labelled ” China, Ganzu , Lanshou , street trees, 1500 m asl, E 103.85°, N 36.05° 2011-09-22, Chi 2011 140“; 3 paratype workers on one pin labelled ” China, Ganzu , Lanshou , street trees, 1500 m asl, E 103.85°, N 36.05° 2011-09-22, Chi 2011 141a“; 2 paratype workers on one pin labelled ” China, Ganzu , Lanshou, street trees, 1500 m asl, E 103.85°, N 36.05° 2011-09-24, Chi 2011 148b“; depository SMN Görlitz.

All material examined. A total of 27 samples with 72 workers were subject to NUMOBAT investigation. These originated from China (25 samples), Russian Far East (1) and Japan (1). For details see supplementary information SI1.

Geographic range. Apparently widely distributed over the Chinese provinces E Qinghai, Gansu, Sichuan and Shaanxi at elevations between 1300 and 3155 m. A probably disjunct population, apparently separated by some 2000 km from the Chinese population, is found in the Russian Far East (42.9°N, 133.9°E, 35 m) and Hokkaido (42.9°N, 143.2°N, 77 m).

Biology. The species occurs in woodland areas and semi-open habitats such as city parks; in highest elevations also in more open situations. Details of biology is unknown but it appears to be rather euryoecious.

Diagnosis ( Tab. 10 , Figs. 101 –102; key):

Probably related to L. sichuense sp. nov. but smaller (CS 888 µm) and longer-scaped (SL/CS 900 1.019). Head moderately elongated (CL/CW 900 1.086). Postocular distance smaller and eye significantly larger than in L. sichuense sp. nov. (PoOc/CL 900 0.238, EYE/CS 900 0.250). Torulo-clypeal distance smaller than in species of the L. coloratus complex (dClAn 900 4.47). Terminal segment of maxillary palp long (MP6/CS 900 0.200). Number of mandibular dents medium (MaDe 900 8.08). Pubescence on clypeus dilute (sqPDCL 900 5.04) and frontal pubescence of medium length (PLF 900 28.6). Setae rather short (PnHL/CS 900 0.130, GuHL/CS 900 0.088) and occurring on most body surfaces in low numbers reminiscent of the situation in the L. obscuratus group (nOcc 900 7.1, nGen 900 2.1, nGu 900 2.4, nSc 900 2.8; nHT 900 4.2, nSt 900 0.4). The surface sculpture on metapleuron and lower propodeum as it is seen in L. coloratus is basically present but the longitudinal carinulae are more delicate and reduced to shorter fragments. Coloration: head mesosoma and gaster either homogeneously medium to dark brown or head and gaster blackish brown and mesosoma less dark; head, mandibles, antennae, metatarsae and tarsae pale yellowish.

Comments. L. longipalpus sp. nov. is separable from Lasius sichuense sp. nov. by any algorithm of NCclustering without classification error. The two apparently disjunct samples from Russian Primorye and Hokkaido do not form a separate branch in NC-Ward and are not exposed as outliers by NC-part.hclust or in a PCA. The classification error by an LDA in 97 individual workers of L. longipalpus sp. nov. and L. sichuense sp. nov. is 0%.

Figures

Figs. 101 and 102: Lasius longipalpus sp. nov.; holotype