Camponotus atricolor

AntWiki: The Ants --- Online
Formica atricolor
Scientific classification (junior synonym of Camponotus piceus)
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Camponotus
Subgenus: Myrmentoma
Species group: lateralis
Species: C. atricolor
Binomial name
Camponotus atricolor
(Nylander, 1849)

Camponotus atricolor casent0179869 p 1 high.jpg

Camponotus atricolor casent0179869 d 1 high.jpg

Specimen Labels

Synonyms

This species is mainly distributed in southern and central Europe and in the southern part of eastern Europe (Seifert 2007) and Turkey. It is a xerothermophilous species living mostly in open, dry grasslands, with nests built in the ground. Workers are highly polymorphic. (Marko et al., 2009)

Identification

A member of the Camponotus lateralis species group. Seifert, 2019: Differential characters of C. atricolor against other blackish species of the group, which are detectable by subjective eye inspection, are the shallow, sometimes nearly absent, metanotal depression, the roughly linear dorsal mesosomal profile and the missing extension of large scape diameter near to its base. However, due the negative allometry of scape base extension, this structure may be missing in large workers of the other four species.

Keys including this Species

Distribution

Marko et al. (2009) - In Romania the occurrence of C. atricolor is reported only from Dobrogea region near the Black Sea (Forel 1906) and from Comana, Giurgiu County, southern Romania (Montandon and Santschi 1910). More recently Gallé et al. (2005) also mention the occurrence of intermediate C. piceus/atricolor specimens from Munar and Bezdin (Secusigiu village), Arad County, western Romania, while reporting the occurrence of C. atricolor sensu Seifert (2007) in the bordering Hungarian region. Based on personal collections from the same region we can also confirm the occurrence of C. atricolor sensu Seifert (2007) in Arad County, although the morphometric data prove its intermediate state: 6 worker, Nădab, Arad County, RO, 20.05.2007, leg. B. Markó, mean PW/PL = 0.739 (±0.06), mean PEW/MW = 0.53 (±0.027).

Seifert, 2019: Steppe zones of Caucasian lowlands, the south of European Russia and the Ukraine, Balkans, Hungary, E Austria and S Moravia (here the northernmost confirmed site at 49.0°N). There is a strong range overlap with Camponotus piceus on the Balkans and some overlap with Camponotus candiotes in the Caucasus.

This is a northern species recorded from Epirus, Macedonia, northern Thessaly and Thrace (Borowiec et al., 2022).

Latitudinal Distribution Pattern

Latitudinal Range: 48.966° to 40.264°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Palaearctic Region: Austria, Azerbaijan, Bulgaria, Greece, Hungary, Romania, Russian Federation (type locality), Türkiye.

Distribution based on AntMaps

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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.
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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.
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Biology

Castes

Seifert, 2019: A minor worker is depicted in AntWeb.org under CASENT0179869 and a major worker under CASENT0179870.

Nomenclature

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

  • atricolor. Formica atricolor Nylander, 1849: 36 (w.) RUSSIA.
    • Type-material: syntype workers (number not stated).
    • [Note: Radchenko, 2007: 37, cites 2w synypes ZMHF.]
    • Type-locality: Russia: “E Rossia meridionali” (no further data) (V. de Motschoulsky).
    • Type-depository: ZMHF.
    • Combination in Camponotus: Roger, 1863b: 1;
    • combination in C. (Myrmentoma): Emery, 1925a: 67; Emery, 1925b: 120;
    • combination in Orthonotomyrmex: Novák & Sadil, 1941: 109 (in key).
    • As unavailable (infrasubspecific) name: Soudek, 1922: 91; Emery, 1925b: 120.
    • Subspecies of lateralis: Forel, 1874: 40; Forel, 1892i: 306; Forel, 1894d: 41; Emery, 1896d: 373 (in list); Ruzsky, 1902d: 7; Ruzsky, 1903b: 302; Forel, 1904b: 380; Ruzsky, 1905b: 254; Forel, 1906c: 189; Forel, 1911d: 355; Emery, 1914d: 159; Wheeler, W.M. & Mann, 1916: 174; Kuznetsov-Ugamsky, 1923: 243; Karavaiev, 1926e: 193; Kuznetsov-Ugamsky, 1929b: 36.
    • Junior synonym of lateralis: Mayr, 1855: 322; Nylander, 1856b: 58; Smith, F. 1858b: 12 (first entry, see below); Mayr, 1863: 399; Roger, 1863b: 1; Dours, 1873: 164; André, 1874: 201 (in list); Forel, 1874: 97 (in list); Emery & Forel, 1879: 448.
    • Subspecies of piceus: Emery, 1925a: 67; Karavaiev, 1927a: 295; Karavaiev, 1927c: 277 (in key); Karavaiev, 1927d: 344.
    • Junior synonym of piceus: Dalla Torre, 1893: 238; Karavaiev, 1936: 190 (redescription); Atanassov & Dlussky, 1992: 222; Arakelian, 1994: 87; Bolton, 1995b: 87; Radchenko, 1997b: 706; Czechowski, et al. 2002: 99; Radchenko, 2007: 37; Gratiashvili & Barjadze, 2008: 131; Legakis, 2011: 28; Kiran & Karaman, 2012: 7; Radchenko, 2016: 334.
    • Subspecies of merula: Novák & Sadil, 1941: 109 (in key).
    • Junior synonym of merula: Bernard, 1967: 344.
    • Status as species: Smith, F. 1858b: 12 (second entry, see above); Arnol'di & Dlussky, 1978: 552; Agosti & Collingwood, 1987a: 58; Agosti & Collingwood, 1987b: 283 (in key); Collingwood, 1993b: 195; Csösz, & Markó, 2005: 229; Markó, Sipos, et al. 2006: 66; Petrov, 2006: 108 (in key); Seifert, 2007: 155 (in key); Werner & Wiezik, 2007: 155; Csösz, et al. 2011: 58; Borowiec, L. & Salata, 2012: 472; Borowiec, L. 2014: 27; Bračko, et al. 2014: 18; Tohmé, G. & Tohmé, 2014: 138; Lebas, et al. 2016: 140; Steiner, et al. 2017: 7; Salata & Borowiec, 2018c: 43; Seifert, 2018: 265; Werner, et al. 2018: 6; Bračko, 2019: 169; Seifert, 2019b: 23; Borowiec, L. & Salata, 2022: 74.
    • Senior synonym of rectus: Seifert, 2019b: 23.
    • Distribution: Austria, Bulgaria, Czech Republic, Georgia, Greece, Hungary, Macedonia, Romania, Russia, Ukraine.
  • rectus. Camponotus lateralis var. rectus Forel, 1892i: 306 (w.) BULGARIA.
    • Type-material: syntype workers (number not stated).
    • Type-localities: Bulgaria: Anchialo, vii.-viii.1891 (A. Forel), Bulgaria: Sozopolis, vii.-viii.1891 (A. Forel).
    • Type-depository: MHNG.
    • [Unresolved junior primary homonym of Camponotus lubbocki var. rectus Forel, 1891b: 217 (Bolton, 1995b: 120).]
    • Subspecies of piceus: Dalla Torre, 1893: 238.
    • Subspecies of lateralis: Forel, 1895d: 229.
    • Junior synonym of piceus: Atanassov & Dlussky, 1992: 222; Bolton, 1995b: 117; Radchenko, 2007: 37; Kiran & Karaman, 2012: 7; Radchenko, 2016: 334.
    • Junior synonym of atricolor: Emery, 1896d: 373; Emery, 1925a: 70; Emery, 1925b: 120; Karavaiev, 1936: 191; Seifert, 2019b: 23.

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

Description

Worker

Borowiec and Salata (2022) - Moderately large, polymorphic; minor worker: HL: 0.920-1.016 (mean 0.964); HW: 0.714-0.809 (mean 0.756); SL: 0.913-1.017 (mean 0.977); EL: 0.230-0.244 (mean 0.236); ML: 1.35-1.51; MW: 0.67-0.73. Color. Body completely black except yellowish explanate anterior margin of pronotum, pronotum never with reddish brown spots laterally, occasionally with yellowish-brown posterolateral corners; usually gena apically with very small yellowish to reddish spot, gaster sometimes brown; antennal scapus yellow, funicle usually with basal 1-3 segments yellowish then subsequent segments gradually darker; coxa brown to black, trochanters mostly brown, femora mostly brown to almost black except yellowish apices, tibiae occasionally yellow, usually yellowish brown to brown, tarsi yellowish to brown (Figs 34.1, 2, 5). Head. Stout, 1.2-1.3 times longer than wide, sides in front of eyes almost straight and slightly converging anterad, behind eyes regularly rounded, posterior margin convex (Fig. 34.5). Clypeus trapezoidal, with anterior margin straight to slightly convex, simple or slightly crenulate, without median emargination, posterior margin in the middle emarginate by frontal triangle, whole surface with diffused microreticulation, appears shiny, covered with short and sparse appressed to decumbent hairs, anterior margin with a row of 6-8 long setae centrally and 4-8 short setae on sides, whole Clypeus with several moderately long erected setae grouping on sides and base of clypeus. Head diffusely to disA tinctly microsculptured, frontal area microreticulate, occipital and temporal area mostly with transverse or circular striation, surface with short and sparse appressed pubescence, appears shiny, gena, frontal and frons and anterior part of occipitum with short to long erected setae, only occipital and temporal areas without setae, ventral side of head with 0-4 moderately long to long erected setae. Scape moderately elongate, approximately 1.3 times as long as width of head, at apex only slightly wider than in base, basal part without horizontal extension, surface diffusely to distinctly microreticulate, shiny, with short and sparse appressed pubescence, without decumbent hairs or erected setae. Funicular segments elongate, thin, first segment 2.1 times as long as wide and 1.8 times as long as second segment, third segment distinctly longer than second, the rest of funicular segments distinctly longer than broad (Fig. 34.5). Eyes moderately big, almost round, 0.24 length of head. Mandibles stout, diffusely microreticulate, surface shiny. Mesosoma. Moderately elongate, 1.9-2.1 times as long as wide, dorsally and laterally distinctly sculptured tending to form transverse, longitudinal, oblique and concentric striation, on sides of pronotum microstriation often diffused, whole surface shiny. In lateral view dorsum with shallow mesonotal groove, often dorsal profile almost linear with only indistinctly marked mesonotal groove, propodeum with flat dorsum approximately 1.5 times as long as wide, posterior margin truncate, in lateral view posterior face and dorsum form distinct angle posterior face not excavate (Figs 34.2, 4). Surface of mesosoma with short and scarce depressed to decumbent hairs, pronotum posterolaterally with 2-6 long erected setae, mesonotum with 10-16 moderately long to long erected setae, propodeum on the whole surface with 12-22 short to moderately long erected setae; the number of erected setae increases with body length, the longest setae with length to 0.224. Waist and gaster. Petiolar scale thick, broad in anterior view, PI = 2.0-2.2, with very convex anterior and flat posterior face, apex rounded; anterior and posterior surface transversely striate, without pubescence or with few very short and very scarce appressed hairs, apical crest with 4-8 very long erected setae. Gaster shorter than mesosoma, tergites with fine transverse microstriation, surface shiny, covered with moderately long but scarce appressed hairs; each tergite with row of, very long erected setae across middle and close to posterior margin, occasionally with few additional erected setae between main rows. Legs. Elongate, hind femora shorter than mesosoma, surface of legs covered with short to moderately long and sparse appressed hairs, inner margin of hind tibiae with row of 2-3 thorns. Ventral surface of fore femora with 3-6 long erected setae.

Major worker: Large, HL: 1.760-1.900 (mean 1.830); HW: 1.740-1.924 (mean 1.832); SL: 1.311-1.349 (mean 1.330); EL: 0.349-0.365 (mean 0.357); ML: 2.19-2.30; MW: 1.21- 1.33. Body color and sculpture as in minor workers but antennae darker , with scapus mostly brown, tarsi often as dark colored as tibiae (Figs 34.3, 4). Head stouter, approximately as long as wide, sides of head softly convex, posterior margin straight (Fig. 34.6). Anterior margin of clypeus slightly serrulate, in the middle with deep semicircular or triangular emargination. Scapus shorter, 0.7-0.8 times as long as width of head. Eyes relatively smaller, 0.20 times as long of head. Setation on head and whole dorsum more numerous than in minor workers, occipital and temporal part of head often with few erected setae, petiolar crest with 8-10 very long setae. Propodeal flat dorsum shorter, approximately 1.3 times as long as wide. Ventral posterior surface of fore femora with 6-10 long erected setae.

Type Material

Seifert, 2019: Investigated were three syntypes of Camponotus atricolor on three different pins labeled ‘Ross.mer. \ Motschulsky 22\ Coll. Nyland \ Motschulsky \ Mus.Zool H:fors Spec. typ. No 5086 Formica atricolor Nyl’, FMNH Helsinki. The syntypes have identical labels except for ‘Spec. typ. No’ which is 5087 and 5088 in the other two specimens.

There is no material in the Musee d'Histoire Naturelle Genève or Naturhistorisches Museum, Basel collection that can be reliably identified as type material for Camponotus lateralis rectus.

Taxonomic Notes

Marko et al. (2009) - This species has a controversial status. Atanassov and Dlusskij (1992) synonymized it with Camponotus piceus due to their findings of intermediate morphs between the two species concerning the depth of the mesopropodeal furrow. A. Radchenko (pers. comm.) also supports this hypothesis on the basis of type material investigation of C. atricolor. Thus, several authors treat it as junior synonym of C. piceus (Radchenko 1997a, Bolton et al. 2006, Werner and Wiezik 2007), while other specialists consider it a valid species (Steiner et al. 2002, Gallé et al. 2005, Seifert 2007). This morph shows clear differences from C. piceus in characters other than just the depth of mesopropodeal furrow (see also Emery 1925), suggesting Camponotus crypsis. Further investigation should elucidate the taxonomic status of the ‘atricolor’ morph.

Seifert (2019) - C. atricolor has been raised to species level by Seifert (1996) and Seifert (2007) but this view did not receive much appreciation by other myrmecologists. It is apparent that C. atricolor, C. piceus and C. candiotes are closely related but only the latter two represent truly cryptic species. The exploratory data analyses NC-part. hclust, NC-part.kmeans and NC-Ward provide a clear separation of C. atricolor from the cluster of siblings formed by C. piceus and C. candiotes. Considering CS and all 12 RAV-corrected shape and seta characters, the error rate on the K = 2 level (atricolor vs. piceus+candiotes) in 124 examined samples is 0 % in NC-part.hclust, 2.4 % in NC-part.kmeans and 0 % in NC-Ward (Fig. 12). The three samples misclassified by NC-part.kmeans were rectified by the controlling LDA if run as wild-cards. The mean error rate of the three exploratory data analyses of 0.8 % is clearly below the 4 % threshold recommended by the Pragmatic Species Concept (Seifert 2014). Thus we have a strong justification for the species status of C. atricolor (see also discussions for Camponotus candiotes and Camponotus piceus).

This clear result on the nest sample level is confirmed by analyses on individual level. The classification error by a LDA considering the five blackish species given in Tab. 3 is only 1.3 % in 77 worker individuals of C. atricolor and 0.8 % in 357 individuals of all five species. The corresponding errors in a leave-one-out cross-validation LDA are 1.3 % and 1.4 % respectively.

The three syntype workers of C. atricolor are allocated to C. atricolor with mean p = 1.0000 if run as wild-card in a 5-class LDA considering the five black species of the group given in Tab. 3.

Forel gave as sampling sites the Bulgarian Black Sea towns ‘Anchialo’ (today named Pomorje) and ‘Sozopolis’ (today Sozopol) and Forel’s description of the mesosomal shape strongly suggests a synonymy with C. atricolor. This view is supported by the fact that C. atricolor is by far the most abundant of the black species along the western coast of Black Sea. Four investigated workers of topotypical material from Sozopolis in the Forel collection in Musee d'Histoire Naturelle Genève (possibly types which Forel missed to designate) are allocated to C. atricolor with a mean posterior probability of p = 0.9975 if run as wild-card in a 5-class LDA considering the five black species given in Tab. 3.

References

References based on Global Ant Biodiversity Informatics

  • Seifert B. 2019. A taxonomic revision of the members of the Camponotus lateralis species group (Hymenoptera: Formicidae) from Europe, Asia Minor and Caucasia. Soil Organisms 91:7–32.