Lasius illyricus

Lasius illyricus
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:	L. illyricus
Binomial name
	Lasius illyricus; Zimmermann, 1935 Specimen Labels
Synonyms
	Lasius alienus pontica Stärcke, 1944;

Information on the ecology and biology of this species is very scarce. Ecological segregation from Lasius emarginatus due to slightly different habitat preferences is witnessed in Greece (Borowiec & Salata, 2013), but no information is available from regions in which L. emarginatus is probably absent (Schifani & Massa, 2020). Lasius illyricus is common in mainland Greece and Ionian Islands, rare in Aegean Islands and Crete, and so far not recorded from Cyclades and Dodecanese. It prefers warm deciduous forests and mediterranean bushes, but in Achaia and Aetolia-Acarnania, it was noted also from mountain pastures and fir forests (Borowiec & Salata, 2021).

Identification

Seifert (2020) - In north Iran, L. illyricus occurs in synoptic sympatry with Lasius persicus. The two species have very similar pigmentation but strongly deviating structural characters; L. persicus has longer setae, much higher setae numbers (on the scape and hind tibia in particular), shorter scapes and terminal segments of the maxillary palps, and smaller eyes.

Borowiec and Salata (2013) - L. illyricus is most similar to Lasius emarginatus. Both occur in similar habitat and appear superficially similar in morphology. Lasius illyricus is easily distinguished from L. emarginatus by pubescence and setation of scapes and external margin of hind tibiae. In L. illyricus the scape in frontal view on dorsal apical 1/3 length has only erect hairs and 2-3erect setae while in the same area in L. emarginatus erect setae predominate. In the same view on the ventral side of the scape suberect hairs with some setae only slightly longer than hairs predominate in L. illyricus while in L. emarginatus setae distinctly longer than adjacent hairs predominate. The difference in chaetotaxy is more clearly visible on the anterior surface of the scape in dorsal view of antenna. In L. illyricus the surface has no to 3-4 erect setae, occasionally to 11 setae in large specimens while in L. emarginatus the setation is more clear with several long erect setae (usually 15-20, up to 34) and only occasionally in small specimens with only 9-10 setae. L. illyricus has sparser setation oh external edge of hind tibia with 6-18 erect setae (mean 13 ± 3), while in L. emarginatus there are 13-27 erect setae (mean 20.8 ± 3.9).

L. illyricus specimens in comparison to southern populations of L. emarginatus are slightly larger (ML 1352 ± 115.9 vs. 1213.7 ± 94.7; HL 1020 ± 72 vs. 1002.3 ± 78.2, HW 981.1±99.5 vs. 952.8±97.6), and more contrastingly coloured with a reddish thorax that is distinctly paler than the head and abdomen. Lasius illyricus is more similar in coloration to northern populations of L. emarginatus than to populations from Greece. The latter are typically dark, with a reddish-brown to brown thorax.

Keys including this Species

Distribution

Seifert (2020) - From the Balkans (42.65°N, 18.07°E) over the southern Ukraine, the southern Caucasus and entire Asia Minor east to the eastern Elburs Mountains (36.867°N, 54.933°E). The altitudinal distribution ranges from sea level up to 1900 m.

This is species common in northern Greece and the Ionian Islands, rare in Crete and the southern Aegean islands (Borowiec et al., 2022).

Latitudinal Distribution Pattern

Latitudinal Range: 44.78333333° to 35.1°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Palaearctic Region: Armenia, Austria, Azerbaijan, Croatia (type locality), Greece, Montenegro, North Macedonia, Russian Federation, Serbia, Türkiye, Ukraine.

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.

Habitat

Borowiec and Salata (2022), for Greece - Lasius illyricus is more ubiquistic than the similar Lasius emarginatus and was observed in a wide variety of habitats. The species is most frequently found in deciduous and coniferous forests. It is also a dominant Lasius species in fir forests. Also often found in stream valleys insides plane forests or in shrubs on mountain pastures, in olive plantations, on trees in mountain villages, on roadsides with mediterranean shrubs, rarely in frygana.

Morphotype 1 prefers warm, luminous areas inside forests. Morphotype 2, like morphotype 2 of L. emarginatus, prefers very dark and humid sites, deep gorges inside dark forests and especially stream banks in such forests and gorges or these in lowlands overgrown with tall reeds.

L. illyricus, in Greece, was observed in the whole range of altitudes, excluding the alpine zone. It was observed on the coasts of the sea, and the highest point of occurrence was observed on the southern slopes of Dikti Mts., Crete at an altitude of 1750 m.

Biology

Borowiec and Salata (2022) - Nests mainly in rocks, stoneworks, under stones or in rotten logs, or under moss that overgrows large stones or trunks at the base of trees. Nest cores often contain a brown carton structure of diversed organic and mineral materials.

Borowiec and Salata (2013) - Prefers broadleaved forests, especially oak and platanus forests, but L. illyricus prefers more open and drier localities and on Korfu it is common in urban areas, gardens and olive plantations (on Korfu olive plantations are different than in other parts of Greece, more like natural-growth forests with extremely high unclipped trees overgrown by epiphytic mosses). On Peloponnese L. illyricus prefers forest margins.

Near Agridi (N Peloponnese, Aroania Mts.) we found nests of both typical L. emarginatus and the L. illyricus form. This was the only locality where we observed sympatric occurrence of both taxa. In Ionian Islands and Central Peloponnese we observed only L. illyricus while in central and northern Greece only L. emarginatus. Halkidiki is an exception where in an extremely warm locality on the Sithona Peninsula near Parthenonas we found only L. lyrics and in Holomontas mountains only L. emarginatus.

Seifert (2020) – Habitat selection by Lasius illyricus is only marginally different from L. emarginatus. In a sympatric area on the Balkans, both species prefer broadleaved forests, especially Quercus and Platanus forests, but there is some trend of L. illyricus to select more open and drier localities. It may occur in urban areas, in gardens and olive plantations. In regions with dryer macroclimate it is found in very shady woods along streams. In north Iran it typically occurs in humid broad-leafed Caspian forest. Reproduction: A mating flight was observed shortly after sunset. Nesting: Nests are in soil, under stones or in rotten logs. Chemistry: Zimmermann wrote in the original description of L. illyricus”...auch fehlt ihnen der L. emarginatus eigentümliche Geruch...“ [”...even so, the peculiar odor of L. emarginatus is lacking...“]. It remains to be checked if this is a constant character or only an ephemeral impression due to the circumstances of observation.

Castes

Worker

Borowiec and Salata 2022. Figures 86.6-7, worker, morphotype 1. Photographed by Lech Borowiec.
Borowiec and Salata, 2013. Figures 17-18.
Borowiec and Salata, 2013. Figure 19-22. Antennal scape. Lasius illyricus: 19. anteral view; 20. dorsal view. Lasius emarginatus: 21. anteral view; 22. dorsal view.

Images from AntWeb


Syntype of LasiusÂ alienus illyricus. Worker. Specimen code casent0905686. Photographer Z. Lieberman, uploaded by California Academy of Sciences.	Owned by MSNG, Genoa, Italy.

Nomenclature

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

illyricus. Lasius alienus subsp. illyricus Zimmermann, 1935: 50 (w.q.m.) CROATIA.
- Combination in L. (Lasius): Borowiec, L. & Salata, 2013: 353.
- Junior synonym of alienus: Wilson, 1955a: 78; Smith, D.R. 1979: 1435.
- Junior synonym of emarginatus: Seifert, 1992b: 34; Bolton, 1995b: 223; Radchenko, 2016: 367; Karaman, M.G. 2011: 89.
- Senior synonym of pontica: Seifert, 2020: 71.
- Status as species: Borowiec, L. & Salata, 2013: 353 (redescription); Borowiec, L. 2014: 86; Salata & Borowiec, 2018b: 157 (in key); Salata & Borowiec, 2018c: 46.
pontica. Lasius alienus var. pontica Stärcke, 1944a: 157 (w.) GEORGIA (Abkhazia).
- Junior synonym of alienus: Wilson, 1955a: 78; Smith, D.R. 1979: 1435; Arakelian, 1994: 117 (error).
- Junior synonym of emarginatus: Seifert, 1992b: 34; Bolton, 1995b: 225; Radchenko, 2016: 367.
- Junior synonym of illyricus: Seifert, 2020: 71.

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 large (CS 991 µm). Head and scape length indices large (CL/CW900 1.082, SL/CS900 1.073); postocular distance small, eye and torulo-clypeal distance large (PoOc/CL900 0.223, EYE/CS900 0.250, dClAn900 5.45); terminal segment of maxillary palp long (MP6/ CS900 0.217). Number of mandibular dents large (MaDe900 8.58). Pubescence on clypeus very dilute (sqPDCL900 5.71); frontal pubescence short (PLF900 22.9). All body parts with much fewer setae than in Lasius emarginatus but in length very similar (PnHL/CS900 0.137, GuHL/ CS900 0.124, nOcc900 7.8, nGen900 4.1, nGu900 4.1, nSc900 2.1, nHT900 7.4). Coloration: similar to the light morph of Lasius emarginatus. Dark morphs have yet to be observed – the darker, more concolorous pigmentation of the small-sized type specimens is probably due to the positive allometry of yellowish or reddish pigments usually observed in Lasius s.str. species.

See table 6 in Seifert 2020 for additional morphometrics. The abbreviated names of various quantitative data shown above are defined here: Seifert 2020 Lasius characters.

Borowiec and Salata (2022) - In Greece, Lasius illyricus forms two distinct eco-morphotypes which differ significantly in morphology and habitat preferences. Morphotype 1: Large, HL 0.861-1.139 (mean 0.993), HW 0.784-1.098 (mean 0.936), ML 1.10 -1.37. Color. Body bicoloured with head and gaster yellowish-brown to brown and mesosoma from yellowish-red or red to reddish brown, sometimes mesosoma as dark colored as head and gaster, as a rule, in nests with small specimens the body color is rather uniform, in nests with large specimens the color is more contrasting. Legs usually yellowish, in the darkest specimens femora and part of tibiae infuscate. Structure and setation. Head broadly oval, only slightly longer than wide, lateral surfaces above eyes convex, occipital margin of head straight to slightly concave. Terminal segment of maxillary palpi elongate with length of sixth segment 0.169-0.232 (mean 0.203). Temporal part of head with numerous long, erected setae also ventral part of head and mesosomal dorsum with several erected setae. Mesosomal dorsum with several long erected setae (length of the longest seta 0.113-0.164, mean 0.137). Below propodeal spiracle up to two erected setae. Anterior surface of antennal scapi usually with 0-4, at most to 11 erected setae in the largest specimens. Exterior surface of hind tibiae with 6-18 erected setae, of mid tibiae with 1-8 erected setae. Ventral surface of femora and anterior surface of fore coxa with several long erected setae. Pubescence of clypeus sparse, frontal and mesosomal pubescence short and sparse. Gaster with dense appressed pubescence and sparse erected setae, surface of gastral tergites distinctly sculptured. Propodeum high and almost conical in lateral view thus metanotal groove very deep.

Morphotype 2: distinctly smaller than morphotype 1, HW 0.492-0.611 (0.556), ML 0.73-0.87. Body always uniformly brown colored, legs indistinctly infuscated. Setation of head, mesosoma and legs sparser than in morphotype 1, especially antennal scapi with less numerous erected setae in extreme case with only 1-2 setae on frontal surface and up to two setae on posterior surface but this reduced number of setae is probably correlated with small size. Clypeal plate more sparsely pubescent than in morphotype 1, promesonotum less convex but propodeum as distinctly as or ever more conical than in morphotype 1.

Type Material

Seifert (2020) - Lectotype worker labelled ”Mt. Petka Dubrovnik YUGOSLAVIA V-1928 S.Zimmerman“, ”type series Lasius alienus illyricus Zimmermann“ (upperside 2nd label), ”unlabelled type Le Tenrant 7.90“(underside 2nd label), ”M.C.Z. CoType 30116“, ”LECTOTYPE desig. by E.O.Wilson“, ”Jan-Jun.2001 MCZ Image Database“; 3 paralectoype workers labelled ”Mt. Petka Dubrovnik YUGOSLAVIA V-1928 S.Zimmerman“, ”Lasius alienus illyricus Zimmermann COTYPE“, ”M.C.Z. CoType 30116“; depository: Museum of Comparative Zoology.

References

References based on Global Ant Biodiversity Informatics

Borowiec L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
Borowiec L., and S. Salata. 2013. Ants of Greece additions and corrections (Hymenoptera: Formicidae). Genus (Wroclaw) 24(3-4): 335-401.
Borowiec L., and S. Salata. 2017. Ants of the Peloponnese, Greece (Hymenoptera: Formicidae). Polish Journal of Entomology 86: 193-236.
Bracko G., K. Kiran, C. Karaman, S. Salata, and L. Borowiec. 2016. Survey of the ants (Hymenoptera: Formicidae) of the Greek Thrace. Biodiversity Data Journal 4: e7945. doi: 10.3897/BDJ.4.e7945
Salata S., L. Borowiec, and A.Trichas. 2018. Taxonomic Revision of the Cretan Fauna of the Genus Temnothorax Mayr, 1861 (Hymenoptera: Formicidae), with Notes on the Endemism of Ant Fauna of Crete. Annales Zoologici (Warsaw) 68(4): 769-808.
Salata S., and L Borowiec. 2017. Species of Tetramorium semilaeve complex from Balkans and western Turkey, with description of two new species of (Hymenoptera: Formicidae: Myrmicinae). Annales Zoologici (Warsaw) 62:279–313.
Salata S., and L. Borowiec. 2018. Taxonomic and faunistic notes on Greek ants (Hymenoptera: Formicidae). Annals of the Upper Silesian Museum in Bytom Entomology 27: 1-51.
Salata S., and L. Borowiec. 2019. Preliminary division of not socially parasitic Greek Temnothorax Mayr, 1861 (Hymenoptera, Formicidae) with a description of three new species. ZooKeys 877: 81-131.