Lasius obscuratus

Lasius obscuratus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Formicinae
Tribe:	Lasiini
Genus:	Lasius
Section:	niger clade
Species group:	niger
Species complex:	obscuratus
Species:	L. obscuratus
Binomial name
Lasius obscuratus Stitz, 1930 Specimen Labels
Synonyms
Lasius gebaueri Seifert, 1992

A soil nesting species often found under stones.

Identification

Seifert (2020) - Palaearctic Lasius s. str. species belonging to the Lasius obscuratus species complex. The morphology of Lasius obscuratus shows a significant structuring in dependence from geography. Sixty-nine specimens from the Baikal region, Mongolia and northeast Tibet (Lasius gebaueri in my conception of 1992) differ from 63 specimens of the remaining western population (L. obscuratus in my former conception) by shorter pronotal setae (PnHL/CS900 0.134 vs. 0.152), larger eyes (EYE/ CS900 0.248 vs. 0.240) and smaller postocular distance (PoOc/CL900 0.229 vs. 0.239).

Keys including this Species

• Key to Palaearctic Lasius s. str.
• Key to Palaearctic Lasius subgenus Lasius s. st.

Distribution

Seifert (2020) - Huge range in Asia between 27°E to 115°E and 34.5°N to 53.2°N. Known from entire Asia Minor, Great Caucasus, Armenia, N Iran (Elburs Mountains), Tadzhikistan, Mongolia and NE Tibet. The altitudinal distribution ranges from 900 to 2600 m in Asia Minor and Great Caucasus, from 1900 to 3160 in Elburs Mountains and W Pamirs, from 1300 to 3400 m in NE Tibet and Gansu, from 700 to 2100 m in Mongolia, and from 536 to 620 m near Lake Baikal.

Latitudinal Distribution Pattern

Latitudinal Range: 44.16666667° to 39.3°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Oriental Region: Tibet (type locality).
Palaearctic Region: Azerbaijan, China, Georgia, Mongolia, Russian Federation.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Seifert (2020) - Lasius obscuratus prefers habitats with xerothermous conditions such as open steppe habitats with diverse phytoassociations, short-grassy pastures, and light steppe forest. It was also found in less dry habitats such as cut meadows, floodplain pastures, sunny willow stands, and montane stunted-growth forest at the tree line. Nest were found in soil, preferentially under stones.

Castes

Worker

Images from AntWeb

Lectotype of Lasius obscuratus. Worker. Specimen code antweb1008435. Photographer Roland Schultz, uploaded by California Academy of Sciences.	Owned by ZMHB, Berlin, Germany.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

• obscuratus. Lasius brunneus var. obscuratus Stitz, 1930: 239 (w.q.) TAJIKISTAN.
  • Junior synonym of alienus: Wilson, 1955a: 78; Smith, D.R. 1979: 1435.
  • Status as species: Seifert, 1992b: 21 (redescription); Bolton, 1995b: 225; Collingwood & Heatwole, 2000: 12; Gratiashvili & Barjadze, 2008: 136; Guénard & Dunn, 2012: 33; Borowiec, L. 2014: 89.
  • Senior synonym of gebaueri: Seifert, 2020: 55.
• gebaueri. Lasius (Lasius) gebaueri Seifert, 1992b: 22, fig. 15 (w.) CHINA (Tibet).
  • Status as species: Bolton, 1995b: 223; Guénard & Dunn, 2012: 33.
  • Junior synonym of obscuratus: Seifert, 2020: 55.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Seifert (2020) - Absolute size rather small (CS 840 µm). Scape and head length indices and number of mandibular dents medium (SL/CS900 0.956, CL/CW900 1.065, MaDe900 8.4). Clypeal pubescence moderately dense (sqPDCL900 4.35). Pronotal setae of medium length (PnHL/CS900 0.140), significantly longer than gular setae (GuHL/CS900 0.091). Dorsum of scape and extensor profile of hind tibia without or only very few semierect setae. It differs from the sister species Lasius psammophilus by longer terminal segment of maxillary palps (MP6/CS900 0.173 vs. 0.145). Coloration: head, mesosoma and gaster dark brown, mandibles, antennae, and legs light yellowish-brown.

See table 3 in Seifert 2020 for additional morphometrics. The abbreviated names of various quantitative data shown above are defined here: Seifert 2020 Lasius characters.

Type Material

Seifert (2020) - Lectotype worker labelled “West- Pamir VII.X. 28 leg.Reinig”, ”Dschailgan 7 x. 1800m“. ”LECTOTYPE designated by E.O.Wilson 1954“, “Lasius brunneus obscurata Stitz lectotype”, “Type”, “GBIF -D/FoCol 2739 specimen and label data documented”; 3 paralectotype workers labelled “West-Pamir VII.X. 28 leg.Reinig”, ”Dschailgan 7 x. 1800 m“ “Lasius brunneus Latr. obscurata St.”; depository Berlin Museum für Naturkunde der Humboldt-Universität.

References

• Seifert, B. 1992b. A taxonomic revision of the Palaearctic members of the ant subgenus Lasius s.str. (Hymenoptera: Formicidae). Abh. Ber. Naturkundemus. Görlitz 66(5): 1-67.
• Borowiec, L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
• Bračko, G. 2019. New data on the ant fauna (Hymenoptera: Formicidae) of Azerbaijan. Caucasian Entomological Bulletin 15, 165–175 (doi:10.23885/181433262019151-165175).
• Liu, C., Fischer, G., Hita Garcia, F., Yamane, S., Liu, Q., Peng, Y.Q., Economo, E.P., Guénard, B., Pierce, N.E. 2020. Ants of the Hengduan Mountains: a new altitudinal survey and updated checklist for Yunnan Province highlight an understudied insect biodiversity hotspot. ZooKeys 978, 1–171 (doi:10.3897/zookeys.978.55767).
• Seifert, B. 2020. A taxonomic revision of the Palaearctic members of the subgenus Lasius s.str. (Hymenoptera, Formicidae). Soil Organisms 92(1): 15-86 (doi:10.25674/so92iss1pp15).
• Snegovaya, N., Shigayev, C. 2021. A checklist of the ants (Insecta, Formicidae) of Azerbaijan Republic. Iranian Journal of Animal Biosystematics 17(2): 179-207 (doi:10.22067/ijab.2022.67343.1000).
• Stitz, H. 1930a. Entomologische Ergebnisse der Deutsch-Russischen Alai-Pamir Expedition 1928 (1). 5. Hymenoptera III. Formicidae. Mitt. Zool. Mus. Berl. 16: 238-240 (page 239, worker, queen described)
• Wilson, E. O. 1955a. A monographic revision of the ant genus Lasius. Bulletin of the Museum of Comparative Zoology.113:1-201.

References based on Global Ant Biodiversity Informatics

• Antonov I. A. 2013. An addition to the myrmecofauna (Hymenoptera, Formicidae) of Baikalian Siberia. Journal of Zoology (in Russian) 92(8): 991-993.
• Borowiec L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
• Collingwood C., and H. Heatwole. 2000. Ants from Northwestern China (Hymenoptera, Formicidae). Psyche 103 (1-2): 1-24.
• Dubovikoff D. A., and Z. M. Yusupov. 2018. Family Formicidae - Ants. In Belokobylskij S. A. and A. S. Lelej: Annotated catalogue of the Hymenoptera of Russia. Proceedingss of the Zoological Institute of the Russian Academy of Sciences 6: 197-210.
• Gratiashvili N., Barjadze S. 2008. Checklist of the ants (Formicidae Latreille, 1809) of Georgia. Proceedings of the Institute of Zoology (Tbilisi) 23: 130-146.
• Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
• Pfeiffer M., R. Schultz, A. Radchenko, S. Yamane, M. Woyciechowski, U. Aibek, and B. Seifert. 2007. A critical checklist of the ants of Mongolia (Hymenoptera: Formicidae). Bonner Zoologische Beiträge 55: 1-8.
• Ran H., and S. Y. Zhou. 2012. Checklist of chinese ants: formicomorph subfamilies (Hymenoptera: Formicidae) II. Journal of Guangxi Normal University: Natural Science Edition 30(4): 81-91.
• Seifert B. 1992. A taxonomic revision of the Palaearctic members of the ant subgenus Lasius s.str. (Hymenoptera: Formicidae). Abhandlungen und Berichte des Naturkundemuseums Görlitz 66(5): 1-67.