Study of the type specimen of Otiorhynchus ambrosii Bertolini, 1893 allowed to reinstate the synonymy: Dodecastichus mastix (Olivier, 1807) [= Otiorhynchus (Dodecastichus) ambrosii Bertolini, 1893; syn. n.]. As a consequence, the following synonymy is also established: Dodecastichus consentaneus (Boheman, 1842) [= Otiorhynchus (Dodecastichus) consentaneus alticola A. Solari & F. Solari, 1915; syn. n.]. A revised list of Dodecastichus Stierlin, 1861 is also drawn up to correct some errors in the latest 2013 catalogue, to include the revised synonymies above, and additional data on all the species of the genus. The alternative original spelling Dodecastichus oligostictus (J. Müller, 1946) is selected over Dodecastichus oligolepis (J. Müller, 1946), both used in the description of this species.

Alonso-Zarazaga (2013: 77) in the recently published volume 8 of the Catalogue of Palaearctic Coleoptera wrote that: “Otiorhynchus ambrosii Bertolini, 1893 is currently placed in synonymy of Dodecastichus dolomitae alticola (A. Solari & F. Solari, 1915)”, and accordingly selected the former name as the valid one for this taxon.

Otiorhynchus (Dodecastichus) ambrosii Bertolini, 1893 was described upon a single specimen from Sella (Trentino, northern Italy) by Bertolini (1893), and was then listed as a valid species by the same author in his checklists of Italian beetles (Bertolini 1899, 1904). This species was unknown by Reitter (1914), and by both the Italian authors Luigioni (1929) and Porta (1932: 16 and 455), who drew up respectively the former a checklist of Italian Coleoptera, and the latter keys to Italian beetle species. Luigioni (1929: 853) placed with a question mark O. ambrosii as a synonym of Otiorhynchus (Dodecastichus) mastix (Olivier, 1807), followed few years later by Porta (1932: 16) who in the addenda on page 455 agreed with the synonymy between O. ambrosii and O. mastix proposed by Lona (1931) during the printing process of the Porta volume. Lona (1931) based his synonymy on the study of the type specimen of O. ambrosii. The same synonymy is of course reported as such in the Junk catalogue by Lona himself (1936).

Subsequently, Angelov (1975), after examining a non-type male specimen from “Italy” surely wrongly identified as O. ambrosii, tentatively considered O. ambrosii as a senior synonym of O. consentaneus alticola (A. Solari & F. Solari, 1915) by writing: “Das in Frage kommende Exemplar hat nichts mit mastix zu tun, da sie aber nicht der Typus ist, kann es nicht entschieden werden, wo sie zu beziehen ist” (Angelov 1975: 54). Indeed, he still used the name alticola as the valid one for this taxon, by him considered a subspecies of O. dolomitae Stierlin, 1862. The Angelov uncertain synonymy quoted by Alonso-Zarazaga (2013) was accepted by none of the Italian authors who subsequently drew up checklists of Italian weevils (Abbazzi e al. 1995, Abbazzi & Osella 1992, Colonnelli 2003, Abbazzi & Maggini 2009). To Dodecastichus was rightly given full generic status by Magnano (1998).

To definitively solve the question we studied the single type of Dodecastichus ambrosii preserved in the Museo delle Scienze di Trento, Italy. It is an immature female pinned through the right elytron (figs 1-2), bearing a white handwritten label “Sella”, a double bordered red label “23”, and another handwritten white label “Ambrosii Bert” (fig. 3). It is, as already ascertained by Lona (1931) a female of the widespread and variable D. mastix, and thus the following synonymy is here again established: Dodecastichus mastix (Olivier, 1807) [= Otiorhynchus (Dodecastichus) ambrosii Bertolini, 1893, syn. rev.].

At this point, arises the question of the taxonomic status of Dodecastichus consentaneus alticola (A. Solari & F. Solari, 1915) from the upper level of the Abruzzes mountains (Di Marco & Osella 2001). It is sure that D. dolomitae has nothing to do with D. alticola, due to the posterior tibiae of the latter not strongly granulate in males, male pigidium lacking of two lateral tufts of centripetal setae, elytra devoid of obvious patches of rather dense setae and less convex in females. All those features are shared with D. consentaneus, and we agree with Di Marco & Osella (2001), who, after examining 1537 specimens of D. consentaneus Boheman, 1842 from the central Apennines, considered alticola just an alpine form of the above species, and thus a synonym of it.

As a result, the following synonymy is here established: Dodecastichus consentaneus (Boheman, 1842) [= Otiorhynchus (Dodecastichus) consentaneus alticola A. Solari & F. Solari, 1915; syn. n.].

Although an in-depth studium of the Italian forms of Dodecastichus is still to be made with the aid of molecular techniques, it should be noted that the populations of D. consentaneus living south of Apennines probably differ at subspecific level from the ones occurring in the Balkans. The same happens for the Apennine forms of D. mastix, which are all more strongly sculptured than the Alpine and Balcanic ones of the same species. As a matter of fact, it is sometime rather difficult to separate the both variable D. consentaneus and D. mastix found in peninsular Italy only considering the sculpture of their dorsal surface, although the female elytra somewhat mucronate and the feebly granulate male posterior tibiae of D. consentaneus versus the broadly acute female elytra and strongly granulate posterior male tibiae of D. mastix let to recognise these species.

To correct some errors by Magnano & Alonso-Zarazaga (2013), and to include the revised synonymies above, we catalogue below the hitherto known Dodecastichus species, all from western Palaearctic, with the format used by our late friend Luigi Magnano who was drawing up a world list of Otiorhynchini, and which in part follows the Colonnelli (2004) catalogue of Ceutorhynchinae of the world in the including of unavailable names, either because being infrasubspecific or incorrect spellings. Abbreviations are the same as in the catalogue of Palaearctic Coleoptera (Magnano & Alonso-Zarazaga 2013). Here we select the alternative original spelling Dodecastichus oligostictus (Müller 1946: 119) over Dodecastichus oligolepis (Müller 1946: 120).

TYPE SPECIES: Otiorhynchus pulverulentus Germar, 1824 by original designation.

Balkans: AL BH ME SB

TYPE LOCALITY. “Prokletje, Zljeb” (Albania, Montenegro).

REPRODUCTION. Bisexual.

Balkans: BH BU CR MC ME SB

TYPE LOCALITY. “Vučja Luka” (Bosnia and Herzegovina).

REPRODUCTION. Bisexual.

Balkans: AL AU BH CR ME

TYPE LOCALITY. «Hercegovina» (Bosnia and Herzegovina).

REPRODUCTION. Bisexual

Italy: Its

TYPE LOCALITY. “Grottaglie” (southeastern Italy).

REPRODUCTION. Bisexual.

Macedonia: MC

TYPE LOCALITY. “Šar planina” (Macedonia).

REPRODUCTION. Bisexual.

Southeastern Europe: AU BH CR IT ME RO SL

TYPE LOCALITY. “Dalmatia” (Croatia).

REPRODUCTION. Bisexual.

Balkans: HU MD RO

TYPE LOCALITY. “Siebenbürgen” (Romania).

REPRODUCTION. Bisexual.

Balkans: BH ME RO SB

TYPE LOCALITY. “Visočica” (Bosnia and Herzegovina).

REPRODUCTION. Bisexual.

Amphiadriatic: AU BH CR IT ME SB

TYPE LOCALITY. “Dalmatia” (Croatia).

REPRODUCTION. Bisexual.

Northern Balkans, Austria, northern Italy: AU BH CR IT

TYPE LOCALITY. “Tyrol” (Austria, Italy).

REPRODUCTION. Bisexual.

Balkans: AL BH CR ME

TYPE LOCALITY. “southern Dalmatia” (Croatia).

REPRODUCTION. Bisexual.

Balkans: BH ME

TYPE LOCALITY. “Sabrani near Volujka” (Bosnia and Herzegovina).

REPRODUCTION. Bisexual.

Balkans: BH CR

TYPE LOCALITY. “Troglav” (Bosnia and Herzegovina).

REPRODUCTION. Bisexual.

Central-eastern Europe: AL AU BH BU CR CZ GE HU IT PL RO SB SK SZ UK

TYPE LOCALITY. “Krain” (Slovenia).

REPRODUCTION. Bisexual.

Central-eastern Europe: AL BH CR HU IT ME RO SI

TYPE LOCALITY. “Dalmatien, Hungary” (Bosnia and Herzegovina, Hungary).

REPRODUCTION. Bisexual.

Croatia: CR

TYPE LOCALITY. “Lika, Jasikovać bei Gospič” (Croatia).

REPRODUCTION. Bisexual.

Eastern Europe: AU BH BU CR CZ GE HU IT HU PL RO SB SK SL UK

TYPE LOCALITY. “Austria, Illyria” (Austria, the Balkans).

REPRODUCTION. Bisexual.

Central-eastern Europe: AL AU BH BU CR CZ GE HU IT LT MC ME PL RO SB SK SL SV(i) SZ UK

TYPE LOCALITY. «Allemagne, Genève» (Germany, Switzerland).

REPRODUCTION. Bisexual.

Croatia: CR

TYPE LOCALITY. «Velebit» (Croatia).

REPRODUCTION. Bisexual.

Southeastern Europe: AU BH BU CR HU IT MD ME PL RO SL SB

TYPE LOCALITY. “Krain” (Slovenia).

REPRODUCTION. Bisexual.

Albania: AL

TYPE LOCALITY. “Okol di Boga” (Albania).

REPRODUCTION. Bisexual.

Italy: IT

TYPE LOCALITY. “Monte Gargano” (southern Italy)

REPRODUCTION. Bisexual.

East Europe: AT BA BG CZ HR HU ITn PL RO UA SQ

TYPE LOCALITY. “Carniolia” (Slovenia).

REPRODUCTION. Bisexual.