Dichotrachelus maculosus Fairmaire, 1869

Meregalli, Massimo & Perrin, Hélène, 2012, On the identity of Dichotrachelus maculosus Fairmaire and D. sabaudus Fairmaire (Coleoptera: Curculionidae: Cyclominae), Zootaxa 3183, pp. 65-68 : 65-67

Dichotrachelus maculosus Fairmaire, 1869

Fairmaire (1869) vaguely localized this species in "Alp. Gall." (French Alps). Stierlin (1878) studied the type and cited the collecting locality (Faillefeu, in the French southwestern Alps) from the specimen label. He also said that it was a 3 (sex inferred from a minute impression in the fifth ventrite, an unreliable trait for sexing Dichotrachelus ) and gave a more complete diagnosis, in which the third tarsal segment was described as bilobed. Based on this trait, Stierlin included D. maculosus in his second group, together with D. imhoffi Stierlin, 1857 , D. rudeni Stierlin, 1853 , D. angusticollis Chevrolat, 1863 , D. stierlini Gredler, 1856 , and D. knechti Stierlin, 1875 (now D. stierlini knechti ). Heyden et al. (1906), Schenkling & Marshall (1929) and Winkler (1932) included D. maculosus among the synonyms of D. rudeni . In contrast Hustache (1929), after examination of several specimens from Faillefeu, placed D. maculosus into synonymy with D. alpestris Stierlin, 1878 , regardless of the indication of bilobed third tarsal segment of the former, contrasting with the simple third tarsal segment of the latter. Hustache failed to note the reversal of priority required to maintain the usage of the younger name, D. alpestris . Osella (1968) did not think it plausible that Stierlin (1878) was in error in his description of the tarsal lobes and rejected Hustache's opinion. Without excluding the possibility of D. maculosus being a valid species, Osella doubtfully referred it to D. stierlini knechti (again without mentioning the required reversal of precedence) rather than to D. rudeni . The type was not examined and no formal synonymy was proposed. Later, Osella (1971) suggested the further possibility that Fairmaire's species could be the senior synonym of D. meregallii Osella, 1971 ; however, in the catalogue of the species and synonyms of Dichotrachelus ( Osella 1971: 553– 562) D. maculosus was not listed, either as a good species or as a synonym.

Since its description and depending on the author, D. maculosus has thus been considered: a valid species, a junior synonym of D. rudeni , a junior synonym of D. alpestris (reversed precedence), a possible junior synonym of D. stierlini knechti (reversed precedence), and the possible senior synonym of D. meregallii .

The type of D. maculosus is conserved at the MNHN, Paris, in the Sédillot collection; it is a Ƥ specimen (Stierlin's observation was incorrect) and belongs to the species currently named D. alpestris Stierlin, 1878 . No information on the number of specimens examined was given by Fairmaire (1869), thus this is considered to be a syntype and is here selected as the lectotype.

Lectotype of Dichotrachelus maculosus Fairmaire, 1869 (here designated): female specimen labeled: 1. F.feu [handwritten, abbreviated form for Faillefeu]; 2. Dichotrach. / maculosus / fairm [hw]; 3. 191 [or 161] [green, printed]; 4. 7 [pink, hw]; 5. Dichotrachelus / maculosus / Fairmaire 1869 / LECTOTYPUS / 2011 Meregalli & Perrin des. [hw, red]; 5. Museum Paris / 1935 / coll. M. Sedillot [pr]. Conserved at the Muséum national d'Histoire naturelle, Paris. Figs 1−4 .

The following new synonymy is here established:

Dichotrachelus maculosus Fairmaire, 1869 [= Dichotrachelus alpestris Stierlin, 1878 ] syn. nov.

The conditions required by art. 23.9.1. ICZN (1999) are not met and D. alpestris cannot be declared nomen protectum. Dichotrachelus maculosus Fairmaire, 1869 must be used as the valid name.

Figures

FIGURES 1 − 4. Dichotrachelus maculosus Fairmaire, lectotype: body (1); foretarsus (2); sternum VIII (3); spermatheca (4). FIGURES 5 − 8. Dichotrachelus sabaudus Fairmaire, neotype: body (5); foretarsus (6); aedeagus (7) and detail of apex (8). Bar: 1 mm.