Lasius silvaticus

Nests have been found in the wood of trees, under stones, in litter and (in a clearcut) in soil.

Identification
Seifert (2020) - Lasius brunneus, Lasius silvaticus and Lasius himalayanus are hypothesized here to represent three cryptic species with different geographic distribution.

Distribution
Seifert (2020) - S Caspian; known from a rather small area between 36.7 and 37.4° N, 54.4 and 55.8°E, and 160 to 900 m a.s.l.

Distribution based on Regional Taxon Lists
Palaearctic Region: Iran.

Seifert (2020) - Habitat selection appears to be similar to its sibling species Lasius brunneus: Seven samples were found in wet and humid Caspian broad-leafed forest and one sample in a city park with trees.

Nomenclature

 * . Lasius silvaticus Seifert, 2020: 47, figs. 3-4 (w.) IRAN.

Worker
Showing all diagnostic characters of the Lasius brunneus species complex. The main difference to L. brunneus is the less sparse and longer pilosity on pronotum (PnHL/ CS900 0.130), underside of head (nGu900 3.6, GuHL/CS900 0.125), propodeum and hind tibia (nHT900 1.6, nSt900 2.9). Accessory differences are the longer head and smaller postocular distance (CL/CW900 1.059, PoOc/CS900 0.235). The coloration is fully comparable to L. brunneus.

See table 1 in Seifert 2020 for additional morphometrics. The abbreviated names of various quantitative data shown above are defined here: Seifert 2020 Lasius characters.

Type Material
Holotype plus 2 paratype workers labelled ”IRAN: 36.7198°N, 54.5813°E, Gorgan 19SE, 853 m, Caspian mild and wet, A.B. Yazdi 2016.06.15 -9“ and ”Holotype (bottom) and paratypes Lasius silvaticus Seifert“; 3 paratype workers ”IRAN: 36.7198°N, 54.5813°E, Gorgan 19SE, 853 m, Caspian mild and wet, A.B. Yazdi 2016.06.15 -24“ and ”Paratypes Lasius silvaticus Seifert“; 3 paratype workers ”IRAN: 37.367°N, 55.817°E, Golestan NP, Galesha canyon, 594 m, forest, nest on tree, Paknia 2007.05.23- 1420“; 3 paratype workers ”IRAN: 37.367°N, 55.817°E, Golestan NP, Galesha canyon, 594 m, forest, nest under stone, Paknia 2007.05.23- 1427“; all material stored in.

Etymology
The species name refers to the woodland habitat.