Formica rufa LINNAEUS, 1761

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 : 152

Formica rufa LINNAEUS, 1761

Formica rufa LINNAEUS, 1761

[original description; YARROW (1954, 1955), photo of type specimen]

Each of the two first descriptions of this ant( LINNAEUS 1758, 1761) are contradictory within themselves. The morphological description of the worker states in 1758: “Thorace compresso toto ferrugineo, capite abdominique nigris.” In 1761, the same statements are repeated and a supplementation is added: “Corpus fuscum. Thorax ferrugineus, compressus, squama intergerina ferruginea, acuminata.” This agrees with the condition in Camponotus herculeanus or Camponotus ligniperda , which both occur in Sweden. In contradiction to the morphological description, LINNAEUS stated “habitat in Europae acervis-acerosis sylvaticis” ( LINNAEUS 1758) and “Piss Myror. SueciStackMyra...Habitat ubique in sylvis, acervos e foliolis acerosis exstruens.” ( LINNAEUS 1761). It is obvious from these data that Linnaeus in both publications more likely intended to give the name F.rufa to those most abundant (“Habitat ubique in sylvis”), needle-thatch building (“Stack-Myra... acervos e foliolis acerosis exstruens.”) and acid squirting (“Piss Myror”) woodland ants. The description of the gyne presented in 1761 reads as follows: “Corpus nigricans. Caput subtus ferrugineum. Thorax ferrugineus dorso fusco. Abdomen segmentis quatuor, primo antice ferrugineo.” This description does not tell much but “Caput subtus ferrugineum” speaks against the two Swedish Camponotus species and is in agreement with the situation in ants of the F. rufa group. According to YARROW (1954), F. rufa group specimens were represented in the collection of the Linnaean Society London by a single worker bearing the label “rufa ex descr.”, two unlabelled winged females, and three unlabelled males. YARROW (1954) published a lectotype fixation in the better preserved of the two winged F. rufa group gynes but he made no statements on its characters. The reasons why he did not fix a lectotype in the only specimen labelled “rufa ex descr.” were not explained. I could not investigate the lectotype.As YARROW (1955) showed a rather good knowledge on the separation of the gynes of F. rufa , Formica aquilonia , Formica lugubris , and Formica pratensis , it appears most probable that he had a specimen at hand which indeed belonged to F. rufa as it is characterized here. Yet, as YARROW (1955) did not separate F. rufa and Formica polyctena , I inspected the picture of the lectotype (specimen number 2870) presented on the homepage of the Linnaean Society (http://linnean-online.org/16186/; retrieved on 31 October 2020). It shows a brilliantly shiny first gaster tergite, a shiny scutellum, and a massive, thickset body. This overall impression corresponds to the gyne morph of monogynous F. rufa and likely precludes the specimen representing F. polyctena . In order to unambiguously dissolve the confusion with Linnaeus’ descriptions, YARROW (1954) argued that “The Commission should use their plenary power to place F. rufa L., 1758 on the list of permanently rejected names and to place instead F. rufa L., 1761 on the Official List of Specific Names in Zoology”. This proposal was accepted by the International Commission of Zoological Nomenclature in an opinion published 2 October 1956.