A taxonomic revision of the Palaearctic members of the Formica rufa group (Hymenoptera: Formicidae) - the famous mound-building red wood ants Author Seifert, Bernhard text Myrmecological News 2021 2021-04-28 31 133 179 http://zoobank.org/0e55c0d7-531a-48d7-a078-148b96bd461d journal article 10.25849/myrmecol.news_031:133 b9f36fb1-1c9d-4af8-96ca-d57973b94862 1997-3500 5582216 0E55C0D7-531A-48D7-A078-148B96BD461D 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 .