Dichotrachelus valesiacus, Stierlin, 1878, Stierlin, 1 878, 1878

Christoph Germann, 2009, About the enigmatic Dichotrachelus valesiacus Stierlin, 1878 (Coleoptera, Curculionidae, Cyclominae), ZooKeys 5 (5), pp. 81-86 : 82-85

publication ID	https://doi.org/ 10.3897/zookeys.5.52
DOI	https://doi.org/10.5281/zenodo.4568762
persistent identifier	https://treatment.plazi.org/id/03D787F1-2825-FF90-A68A-FC89FC61FB8B
treatment provided by	Plazi
scientific name	Dichotrachelus valesiacus
status

Treatment

Results and discussion View in CoL

Material examined: 1 male with the following indications: “ Val Entremont St. Bernhard D. valesiacus Stierl .” ( Fig. 1 View Fig. 1 ) From the Stierlin collection, deposited in the collection of the DEI.

Body length (c.r.e.): 2.9 mm, maximal width: 1.4 mm.

The most conspicuous traits providing evidence for the synonymy are depicted.

Habitus: Fig. 2 View Fig. 2 a

Right protarsus: Fig. 3 View Fig. 3 a Aedeagus: Fig. 4 View Fig. 4 a, c Internal sac: Fig. 5 View Fig. 5 a Remarks: The specimen is in a comparable good condition, the following parts of the body are missing: right hind tarsus, right middle tarsus (from the third tarsal segment on), left fore tarsus, claw segment.

The single male specimen of D. valesiacus is the only one present in the Stierlin collection. The specimen fits in every detail the description of Stierlin (1878: 416-417). Stierlin did not mention any typical exemplars in the first description. Only later in his “Fauna coleopterorum helvetica”, he mentioned in a footnote “Bei dem einzigen Exemplare, das ich kenne...” which shows that only a single specimen was known to him ( Stierlin 1898: 271). According to articles 72.4.1.1 and 73.1.2 of ICZN (2000) this specifies unambiguously the holotype by monotypy. Hence, the use of the recommendation 73F with the designation of a lectotype is not necessary. However, it should be mentioned that the only specimen of D. valesiacus was thought to be a female since the revision of the genus ( Osella 1970). The examination of the type revealed that it is a male specimen belonging to D. verrucosus ( Kiesenwetter, 1852) , distributed in the eastern and central Pyrenean Mountains in France ( Kiesenwetter 1852, Osella 1970) and Spain ( Meregalli 1987). One male specimen of D. verrucosus with the following indications was used for comparison: “Pyrénées Or. Dichotrach. verrucosus ” from the Rätzer collection (NMBE) ( Figs 2 View Fig. 2 b, 3b, 4b, d, 5b).

The new synonymy is established: D. verrucosus ( Kiesenwetter, 1852) View in CoL = Dichotrachelus valesiacus Stierlin, 1878 View in CoL syn. nov.

As shown, the unraveled D. valesiacus is in fact D. verrucosus . Since D. verrucosus is exclusive to the eastern and central Pyrenean Mountains, the type of D. valesiacus was evidently wrongly labeled. This mistake confused Stierlin (1878) when he referred it to a new species, although D. verrucosus was included in his revision.

The Swiss weevil fauna has lost with the present established synonymy the only species named after the most popular region for zoologists, the Valais.