Eusphalerum minutum ( FABRICIUS 1792)

Zanetti, A., 2008, Synonymies in the European Omaliinae, with notes on distribution (Coleoptera: Staphylinidae), Linzer biologische Beiträge 40 (1), pp. 979-992 : 980-981

Eusphalerum minutum ( FABRICIUS 1792)

Sylpha minuta FABRICIUS 1792. Lectotype female (here designated) labelled "minuta" (original) / Lectotype Sylpha minuta Fabricius, 1792 des. Zanetti, 2008 / Eusphalerum minutum ( Fabricius, 1792) det. Zanetti 2008; 1 paralectotype male, on the same label, without abdomen and part of legs (ZMUC) ( Fig. 31 ).

Omalium ranunculi GRAVENHORST 1802 . Lectotype male (here designated) labelled 6921 / Omalium ranunculi Gravenhorst des. Zanetti 2007 / lectotypus (red) / Eusphalerum minutum (F.) det. Zanetti 2007 / minutum Er. (sic) Silpha m. F. - O. ranunculi Gr. (original label), 3 paralectotypes males and 4 paralectotypes females labelled Hist-Coll. ( Coleoptera ) Nr. 6921 Anthobium minutum Erichs. Europa Zool. Mus. Berlin (recent label)/ Omalium ranunculi Gravenhorst des. Zanetti 2007 / paralectotypus (red); one paralectotype male has also the label "paludosum Heer Helvet. Heer", original) (MNHUB) (Fig. 2).

Anthobium petzianum BERNHAUER 1929 nov.syn. Type (female) Schoberstein Austria sup. Mont. Petz / 4352 (FMNH) (Fig. 8).

Anthobium jurassicum JARRIGE 1845 nov.syn. Type (male) Juogne Jura VII.26/ Coll. Ph. Naude / Type (red)/ Museum Paris; 1 paratype (male, labelled as cotype), 1 specimen (female, probably paratype, not labelled as paratype) with the same locality label ( MNHNP) (Fig. 1) .

Eusphalerum subjurassicum COIFFAIT 1959 nov.syn. Paratype (male) St Paul B.A. L. Levasseur coll./ subjurassicum Coiff. / Paratype (red)/ Museum Paris (MNHNP) (Fig. 3).

C o m m e n t s: The typical series of Eusphalerum minutum includes one damaged male and one female. As the male is without aedeagus, the female is designated as the lectotype. The shape of the elytra allows a positive identification. The typical series of O. ranunculi confirms the synonymy with O. minutum .

E. petzianum was described based on a female from Schoberstein "in der Nähe der Stadt Steyr in Oberösterreich ". Other records from Austria (Salzburg, Steyermark) are reported in HORION (1963, misquoted by HERMAN (2001) that includes also Switzerland, France, Austria and Italy in the distribution of the species). The main character distinguishing E. petzianum from E. minutum is body size, almost double (3.2 mm). Also, form and puncturation of the pronotum are supposedly distinctive, with the pronotum shorter, and the puncturation twice as coarse and dense. This species was considered a possible junior synonym of E. minutum by ZANETTI (1987). The examination of material of E. minutum from most parts of Europe confirms this opinion, the type of E. petzianum is a large specimen of E. minutum (size range reported in the literature is 2-2.5 mm, see COIFFAIT 1959 and ZANETTI 1987; LOHSE 1964 does not indicate the size). Coarse and dense puncturation is often present in large specimens of Eusphalerum . Elytra are within the range of variability of E. minutum (Fig. 8).

Eusphalerum jurassicum was described as close to E. anale (ERICHSON 1840) , the main differential charactes being the completely different shape of the aedeagus. No reference to E. minutum is given in the original description. COIFFAIT (1959) includes E. jurassicum in the "groupe jurassicum " of the subgenus Abinothum and E. minutum in the "groupe minutum " of the subgenus Eusphalerum . He distinguishes these subgenera by the length of the elytra, a very variable character that is inadequate for defining distinct phyletic lines in Eusphalerum . On the other hand, the drawings of the aedeagus, even if very schematic, show that E. jurassicum and E. minutum are very closely related. LOHSE (1964) follows COIFFAIT and includes E. jurassicum in the subgenus Abinothum and E. minutum in the subgenus Eusphalerum . According to ZANETTI (1987), Abinothum is not a distinct subgenus in Eusphalerum and E. jurassicum is closely related to E. minutum . HERMAN (2001), in the section on E. jurassicum , misquotes Lohse (l.c.) as follows: " Lohse, 1964: 36 ( Eusphalerum ; subgenus Pareusphalerum; characters; central Europe)". The true page is 32 and the subgenus is Abinothum. SMETANA (2004) follows Herman (l.c.) and includes E. jurassicum in the sugenus Pareusphalerum. In the original description the typical series of E. jurassicum includes 2 males (type, paratype) and 2 females (two paratypes). I have examined the type, 1 male paratype and 1 female not labelled as paratype with a locality label identical to the one of the type. They all are evidently small specimens of E. minutum , a species widely distributed in Central Europe, whose size range is usually 2-2.5 mm (see above). Possibly Jarrige was fooled by the small size of the specimens (1.7 mm), but the aedeagus allows a reliable identification as E. minutum (Fig.1, the paratype is represented because the aedeagus of the type, dissected by Jarrige himself, is strongly dried and inadequate for a slide preparation). Differences that can be observed in the shape of the aedeagus are artefacts resulting from the conservation of the specimen, strongly dried specimens have sunken lateral margins in the median lobe (Figs 1, 2 and 3). Also, the shape of the apex of the elytra of the female is within the range of variability of E. minutum , it is not sinuate near the apex of the suture as is often the case in small specimens (Figs 5-8).

Eusphalerum subjurassicum was described based on specimens from the Basses-Alpes (Saint-Paul-sur-Ubaye leg. Fagniez, coll. Levasseur). The external characters supposedly distinguishing it from E. jurassicum (head with two normal frontal tips, without furrows nor fore small tips) and the shape of the aedeagus are within the variability range of E. minutum (Fig. 3). The examination of a male paratype confirms the synonymy.

Figures

Fig. 31: Eusphalerum minutum (FABRICIUS), lectotype female (right) and paralectotype female (left).