Lasius silvaticus

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

Identification
Seifert (2020) - Palaearctic Lasius s. str. species belonging to the Lasius brunneus species complex. 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.