Key to the Westpalaearctic Camponotus lateralis species group

This worker key is based on: [[Media:Seifert, B. 2019. A taxonomic revision of the members of the Camponotus lateralis species group.pdf|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. (DOI 10.25674/so-91-1-02).]]

The key for this group of ants, and the study it is from, highlights numerous problems associated with describing and carrying out taxonomic revisions in the genus  Camponotus. There can be issues with vague, older descriptions of subgenera, species groups and species. This can also be coupled with any or all of the following: species and subspecies described from a lone type, lost or difficult to access type material, extensive variation within and between species, caste polymorphism, and type labels that only note a poorly delimited type locality. For some species of  Camponotus that are now better collected, and for some groups of similar species with problematic but known variation, can be difficult to definitively determine to species without a nest collection that includes a range of castes. Reconciling the identify of many older described species and subspecies, and their types, can be difficult because there is not enough information or specimens to make sound taxonomic decisions. As more revisionary studies are completed in Camponotus the number of species and subspecies that must be left as is, and either noted as a problem or assigned a status of Incertae Sedis, will increase.

Seifert's preface for his – "Key to the workers of the Camponotus lateralis species group in Europe, Asia Minor and Caucasus": It should be clear that a very simple key cannot achieve determinations as safe as the application of complex multivariate analyses of complete character sets. The very strong, often biphasic allometries, color polymorphism, size dimorphism as well as shape and setae polymorphism complicate the situation and do not allow simple answers to difficult questions. In order to achieve some simplicity, the key uses absolute measurements. All inputs to discriminant functions have to be in millimeters with exception of RipD where input in micrometers is required.

More about this group is detailed here: Camponotus lateralis species group

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1

 * A. Vertex in the majority of specimens in a nest sample not completely blackish; reddish pigmentation at least in patches appearing, whole head often completely reddish brown. Microripples on dorsum of 1st gaster tergite more widely set: RipD 8.8 – 14.1 μm. If microripples are more densely set (Camponotus rebeccae), then whole vertex reddish brown . . . . . 2


 * B. Vertex completely blackish. If some small parts of anterior vertex have reddish pigmentation (Camponotus dalmaticus), then microripples on dorsum of 1st gaster tergite are densely set with RipD 7.59 ± 0.55 . . . . . 6

2
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 * A. Dorsal propodeal plane wide; scape base extension very strong, scape long; mesosoma wide. Discriminant 21.98*PrW+6.897*ScI+4.015*MW–9.25*CL0.249*SL–6.684 > 2 [error 0% in 6 specimens]. Asia Minor . . . . . Camponotus honaziensis


 * B. Dorsal propodeal plane less wide; scape base extension less strong (except C. lateralis morph 1); scape shorter; mesosoma narrower. Discriminant < 2 [error 1.6% in 191 specimens] . . . . . 3

3
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 * A. Discriminant 0.712*nPr+21.46*CL–14.462*CW–17.898*PeW+297.0*RipD–6.225 > 2.3 [error 0% in 9 specimens]. Dorsal propodeal plane in dorsal view trapezoid, in posterior part much wider than anterior; bilateral sum of setae on mesonotum and propodeum dorsal of spiracle 19.2 ± 5.7 (count also basal pits of detached setae!). Asia Minor . . . . . Camponotus anatolicus


 * B. Discriminant < 2.3 [error 1.7% in 182 specimens]. Dorsal propodeal plane in dorsal view posteriorly not clearly wider than anteriorly; bilateral sum of setae on mesonotum and propodeum dorsal of spiracle 8.3 ± 3.7 (count also basal pits of detached setae!) . . . . . 4

4
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 * A. Distance of microripples on dorsum of 1st gaster tergite small, RipD 7.1–9.5 μm. Discriminant 6.107*CL–24.624*PrL+954.7*RipD–6.81 < 2.35 [error 0% in 32 specimens]. Crete, Cyprus, Asia Minor, Syria . . . . . Camponotus rebeccae


 * B. Distance of microripples on dorsum of 1st gaster tergite larger, RipD 9.1–13.7 μm. Discriminant > 2.35 [error 0% in 149 specimens]. Morphs of Camponotus lateralis, co-occurring in 16% of nests. North Mediterranean from Iberia to Turkey . . . . . 5

5
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of propodeum only weakly convex in lateral view. . . . . Camponotus lateralis morph 1
 * A. Less hairy and pubescence shorter; unilateral number of setae on dorsal plane of scape low: nSC 1.7 [0–5]; scape base extension large: ScI 1.22 [1.04–1.40]; scape and dorsal propodeal area more elongated. Discriminant 7.837*ScI–0.525*nSc+7.407*Sl+7.275*PrL–17.675 > 0 [error 0% in 86 workers]. Major workers with sinusoidally curved frontal carinae and the dorsum


 * B. Very hairy and with longer pubescence. Unilateral number of setae on dorsal plane of scape larger: nSC4.29 [0–11.5]; scape base extension small: ScI 1.04 [1.00-1.10]; scape and dorsal propodeal area less elongated. Discriminant < 0 [error 0% in 64 workers]. Majors with less sinusoidally curved frontal carinae and the dorsum of propodeum strongly convex in lateral view . . . . . Camponotus lateralis morph 2

6
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 * A. Scape very long relative to width of mesosoma and dorsal propodeal plane. Discriminant 28.141*SL–12.125*MW–16.724*PrW–15.683 > 2.1 [error 0% in 32 specimens]. Balkans . . . . . Camponotus heidrunvogtae


 * B. Scape clearly shorter relative to width of mesosoma and dorsal propodeal plane. Discriminant < 2.1 [error 0% in 321 specimens] . . . . . 7

7
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 * A. Mesonotum and propodeum with very few setae: nMn2.0 [1–5.5], nPr 2.15 [1–4.5]; width of dorsal propodeal plane and petiole relative to CL smaller. Discriminant 0.238*nMn+0.192*nPr–13.124*CL+28.124*PrW+5.228*PeW+2.731 < 0 [error 0% in 67 specimens]. Balkans northwest to S Switzerland . . . . . Camponotus dalmaticus


 * B. Mesonotum and propodeum more hairy: nMn 4.8 ± 2.4, nPr 7.40 ± 3.4; width of dorsal propodeal plane and petiole relative to CL larger. Discriminant > 0 [error 0.8% in 253 specimens] . . . . . 8

8
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 * A. Extension at scape base absent or very weak; metanotal depression very shallow. Discriminant 16.35*ScI+33.25*MGr+5.962*CW–0.146*nPr–10.773*PeW–20.913 < 0 [error 1.3% in 76 workers and 0% in 30 nest sample means with at least 2 workers]. Pannonian Plane, Balkans, Ukraine east to Caucasus . . . . . Camponotus atricolor


 * B. Extension at scape base more developed; metanotal depression deeper. Discriminant > 0 [error 4.0% in 177 workers and 0% in 68 nest sample means of at least 2 workers] . . . . . 9

9
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 * A. Crete, Asia Minor, Caucasus. Discriminant 13.74*ScI+8.383*CL+8.565*SL–43.51*MGr–26.46*PrL–19.751 < 0 [error 2.5% in 40 workers] . . . . . Camponotus candiotes


 * B. South Temperate and Mediterranean Europe. Discriminant > 0 [error 2.2% in 137 workers] . . . . . Camponotus piceus