Trichius gallicus Dejean, 1821 (valid species name)

The oldest available name for the species called Trichius rosaceus Voet by the authors listed above and others is Trichius gallicus Dejean, 1821. Dejean (1821: 61) introduced Trichius gallicus as the valid name of Trichius fasciatus sensu Olivier. The type locality is Paris. Since no description was given, Dejean's name has long been considered a nomen nudum (Sherborn 1926: 2628; but see Hoeven 1856: 510) and therefore has been credited to Heer (1841), who supposedly was the first to publish a description of Trichius gallicus. However, Dejean’s (1821) reference to " Fasciatus. Ol." fulfils the requirements of Article 12.2.1 (International Commission on Zoological Nomenclature 1999) for availability by indication: "a bibliographic reference to a previously published description or definition". The reference to Olivier's description of Trichius fasciatus, even if not fulfilling modern standards for bibliographic references, unambiguously refers to Olivier's (1789: Cétoine 61) description of Cetonia fasciata. However, the identity of Olivier's species cannot be determined from the description as it fits any of the European Trichius species. The abdomen is described as black, which is true for the females of all European species and also for the males of T. fasciatus. In his references, he refers to Voet's description, but also to Linnaeus's Trichius fasciatus. Olivier certainly subsumed at least two species under the name Cetonia fasciata. However, we can unequivocally determine the identity of Trichius gallicus Dejean, 1821, since later, Dejean (1829) himself, in a so far overlooked paper, described in detail the three Trichius species he mentioned in his catalogue. “ Trichius abdominalis. Dej.” from Austria is the species that we currently know as Trichius sexualis Bedel, 1906 (see Krell 2010) since Dejean (1829) describes the male abdomen of this species "dont les taches jaunes de l'avant-dernier segment sont plus grandes [in comparison to T. gallicus], et dont les segments antérieurs sont marqués d'une bande transversal, jaune, un peu écrancrée postérieurement dans son milieu." Dejean's T. fasciatus is, without doubt, Trichius fasciatus (Linnaeus, 1758) as this is the only species occurring in Sweden (Smetana 2006) and, as Dejean (1829) describes "Le dessous de l'abdomen du male n'a aucune tache jaune." Trichius gallicus (= Trichius rosaceus Kraatz) occurs in the former Swedish territories in Pomerania (Köhler & Klausnitzer 1998), but they were no longer Swedish at the time of publication of Dejean’s catalogue (Hacker & Hardenberg 2003), and Dejean (1829) did not know this species from northern Germany. The third species, T. gallicus, is identical to the species we currently know as T. rosaceus or T. zonatus, because the male abdomen of T. gallicus "présente les taches jaunes indiquées par MM. Serville et comte de St.-Fargeau." Le Peletier de Saint-Fargeau & Serville (1828: 703) described under “Trichie fascié, T. fasciatus ”, which they misinterpreted, the abdomen of T gallicus: “Le mâle a l’avant-dernier segment de l’abdomen en dessous […] chargé à sa base de deux sections de cercle garnies d’écailles serrées, jaunâtres.” Dejean had distinguished the three central European species correctly. Heer (1841) interpreted Dejean’s Trichius gallicus correctly. Trichius gallicus Dejean, 1821 is the valid name for the species that is currently known as T. rosaceus and T. zonatus. Until the mid 1900s, Trichius gallicus had been in use as valid name mainly in western Europe and North Africa, e.g., by Houlbert & Monnot (1910), Bedel (1911), Martínez de la Escalera (1914), Doflein (1921), Abot (1928; “ T. zonatus Germ. var. gallicus Heer ”), Sainte-Claire Deville (1935; “[zonatus Germ.] var. gallicus Heer ”), and Paulian (1941, 1959; “ Trichius zonatus subsp. gallicus Heer ”), until it was synonymized with T. rosaceus by Janssens (1960: 353). After Janssens, T. gallicus has rarely been used, but was not completely forgotten (see Bobîrnac et al. 1999: " Trichius zonatus Germ., ab. gallicus Herr "; Ádám 2003: “ Trichius zonatus var. gallicus Heer, 1841 ”; Davidts 2006: " Trichius gallicus "). The name was used on a French postage due stamp in 1982 (see Lucht 1987). Its reinstatement, even with the different author Dejean, reviving the former use after a gap of 70 years, is unlikely to cause major confusion.