Formica major NYLANDER, 1849

Seifert, Bernhard, 2021, A taxonomic revision of the Palaearctic members of the Formica rufa group (Hymenoptera: Formicidae) - the famous mound-building red wood ants, Myrmecological News 31, pp. 133-179 : 156

Formica major NYLANDER, 1849

Formica major NYLANDER, 1849 [type investigation]

This taxon was described from the environs of Helsingfors (Helsinki). Three syntype workers on one pin labelled “Zool. Mus. H:fors Spec. typ. No 5423 Formica major Nyl. “, “major Nyl piniphila Schenck rufa auctt nec Bondr.”, “Mus. Hels. N:o 2676” do not carry an information on the sampling locality but the specimens fully match the morphological description of NYLANDER (1849). Considering their numeric data and by subjective impression, the type series of F. major cannot be hybrids Formica polyctena × rufa but represents either F. polyctena , Formica aquilonia × polyctena hybrids or backcrosses. This morphology-based idea is fully in line with the existence of large hybridization and introgression zone in southern Finland shown by nuDNA data ( BERESFORD & al. 2017). Run as wild-cards in a two-class LDA considering the characters CS, CL / CW 1750, SL / CS 1750, nCH 1750, OccHL 1750, nGu 1750, GuHL 1750, nPn 1750, mPnHL 1750, nMes 1750, nMet 1750, MetHL 1750, nPr 1750, SL / Smax 1750, EyeHL 1750, and nSc 1750, the type sample is allocated with p = 0.4867 to F. polyctena and with p = 0.5133 to the hybrid cluster. The marginal position in the hybrid cluster suggests F. major to represent a backcross of a F. aquilonia × polyctena hybrid with F. polyctena . A PCA plot considering the characters CS, SL / CS 1750, OccHL 1750, GuHL 1750, SL / Smax 1750, EyeHL 1750, and nSc 1750 provides the same impression ( Fig.24 ). These investigations considered 27 nest samples and 148 workers of F. aquilonia × polyctena hybrids or backcrosses and 57 nest samples with 217 workers of F. polyctena . See also section “ Formica aquilonia YARROW, 1955 ” (p. 158) and Figure 25 .

Figures

Fig.24: Position of the type samples of Formica major NY- LANDER, 1849 (MA) and Formica constricta KARAVAJEV, 1929 (CO) in a principal component analysis considering 58 nest samples of Formica polyctena (black squares) and 27 nest samples of Formica aquilonia × polyctena or backcrosses (white dots). The F. polyctena sample deeply placed within the hybrid cluster is aberrant and cannot be a hybrid for zoogeographical reasons. Seven phenotypic characters were considered.

Fig.25: Position of the type samples of Formica major NY- LANDER, 1849 (MA) and Formica constricta KARAVAJEV,1929 (CO) in a linear discriminant analysis considering 58 nest samples of Formica polyctena (black squares), 27 nest samples of Formica aquilonia × polyctena or backcrosses (white dots), and 75 nest samples of F. aquilonia (black rhombs). The type samples were run aswild-cards.Sixteen phenotypiccharacters were considered.