Gyrinus glaucus Klug, 1834

Fery, Hans & Hájek, Jiří, 2021, Nomenclatural and taxonomic notes on some species of Gyrinidae (Coleoptera), Acta Entomologica Musei Nationalis Pragae 61 (1), pp. 55-71 : 57-58

Gyrinus glaucus Klug [ Orectogyrus ] and Gyrinus glaucus Aubé [ Macrogyrus ]

Homonymy. Gyrinus glaucus Aubé, 1838b: 657 (currently in subgenus Andogyrus of genus Macrogyrus ) is a junior primary homonym of Gyrinus glaucus Klug, 1834 : pl. XXXIV (currently in Orectogyrus Régimbart, 1884 ), and thus Aubé’s name is permanently invalid. However, the two names apply to taxa not considered congeneric after 1899 and the junior homonym must not be automatically replaced (Article 23.9.5 of the ICZN).

– Klug’s taxon was included by Bඋඎඅඅඣ (1835: 238, footnote) in the subgenus Orectochilus of genus Gyrinus , in the genus Orectochilus by Aඎൻඣ (1838b), and in the genus Orectogyrus since RඣǤංආൻൺඋඍ (1884).

– Aubé’s taxon has been included in the genus Macrogyrus since RඣǤංආൻൺඋඍ (1883a), in the genus Andogyrus since OർIJඌ (1924), and in Macrogyrus (Andogyrus) since Gඎඌඍൺൿඌඈඇ & Mංඅඅൾඋ (2017).

It follows that Macrogyrus borrei Régimbart, 1883 a: 436 – an available junior subjective synonym – cannot replace glaucus Aubé. According to Article 23.9.5 of the ICZN, this case must be ‘… referred to the Commission for a ruling under its plenary power’ and we propose conservation of the junior homonym.

Gyrinus marginatus Germar

and Gyrinus marginatus Aubé [ Aulonogyrus ]

History of classification. Gൾඋආൺඋ (1823: 32) published his taxon as ‘ Gyrinus marginatus Eschscholtzii ’ and with the words ‘Affinis Gyr. natatori, ...’ and ‘... elytris distincte striato-punctatis, margine infero ferrugineis. Habitat in Livonia.’ [= similar to Gyr. natator , ... elytra with distinct puncture lines, ventral margin [= epipleura] ferruginous. Occurring in Livonia]. (Livonia is a landscape in the Baltics which encompasses more or less the present southern Estonia and northern Latvia). Germar’s name may be a nomen dubium, but it is an available name. It was dealt with in about 70 works and almost always treated either as aberration, variety, or synonym of G. natator (Linnaeus, 1758) (or of G. mergus Ahrens, 1812 which is currently treated as a junior subjective synonym of G. natator ). Exceptions are SർIJආංൽඍ (1844: 12), who treated it as a valid name with author ‘Eschs.’ [= Eschscholtz] in a simple list of taxa, and Dൾඃൾൺඇ (1833: 58, 1836: 66), who gave the name ‘ marginatus Eschsch. ’ as a synonym of G. marinus Gyllenhall in his catalogues.

Homonymy. Gyrinus marginatus Aubé, 1838b: 714 (currently in Aulonogyrus Motschulsky, 1853 ) is a junior primary homonym of G. marginatus Germar, 1823: 32 , and thus Aubé’s name is permanently invalid. Article 23.9 of the ICZN cannot be applied which would allow conserving Aubé’s name and to suppress Germar’s name as we know of about 35 works in which Aubé’s name is used as valid with only 13 of them were published during the last 50 years.

We are convinced that the stability of the nomenclature is not threatened if the name of this rarely cited taxon is replaced be a new replacement name. In honour of Charles Aubé we propose the name Aulonogyrus charlesaubei nom. nov. for the species which was so far called Aulonogyrus marginatus ( Aubé, 1838) .

Notes. Bඋංඇർκ (1955a: 381) gave the name ‘ Aulonogyrus capensis Wallengren, 1881: 15 ’ in a ‘synonymy list’. WൺඅඅൾඇǤඋൾඇ (1881: 15) identified some Gyrinus as G. capensis Thunberg, 1781 (now in Aulonogyrus ). Bඋංඇർκ (1955: 381) after studying Wallengren’s material found that these specimen(s) were misidentified specimen(s) of Aulonogyrus marginatus Aubé. It is therefore clear that WൺඅඅൾඇǤඋൾඇ (1881) did not describe any new taxon and the name is thus unavailable.

Gyrinus species described

by Oඅංඏංൾඋ (1792 and 1795)

History of classification. Oඅංඏංൾඋ (1792: 701 and 702) and Oඅංඏංൾඋ (1795: 11 and 13) described three species of Gyrinus twice: Gyrinus striatus (currently in genus Aulonogyrus ), Gyrinus longimanus (currently in Dineutus ) and Gyrinus bidens (currently in Gyretes ). The text of the

descriptions of each species is almost identical in both publications. We are aware that such ʻsecond descriptionsʼ are not accepted as available new names by several colleagues. Since this problem is not regulated by the ICZN, we follow here the proceeding which is described in the Introduction of the World Catalogue of Dytiscidae (Nංඅඌඌඈඇ & Hගඃൾκ 2020: 13; see also older versions of the Catalogue): A few authors like Aubé, Guignot, Régimbart and Sharp have in some of their works described the same species twice. The names produced in this way are both junior synonyms and junior homonyms; they are permanently invalid, but they are nevertheless available names, see Article 10.6 of the ICZN. In each such case two different names exist; however, such a junior synonym and homonym is only included in the Catalogue (and not accepted as redescription) if it explicitly is given as a new taxon and no reference is being made to the older description (not cited literally). A similar case in Gyrinidae are the species described by Aඎൻඣ (1838a, 1838b), see Fൾඋඒ & Hගඃൾκ (2016: 648 and Table 1).

We want to add that Oඅංඏංൾඋ (1795) in the Gyrinidae part (pp. 1–14) gave no hint on any species of the family described in his previous work. However, instead he referred to the work from 1791–1792 in several other species (e.g. Oඅංඏංൾඋ 1795: 23 wrote: ʻDytiscus ciliatus ... Dict. ins. Dytique. no. 23. [= number of D. ciliatus in Oඅංඏංൾඋ (1791)]ʼ).

Since no doubts exist about the identity of Gyrinus longimanus and G. bidens , and the names are not threatened by any other names we are not dealing with them in detail in the present paper and focus only on Gyrinus striatus (see below).