Plateumaris tenuicornis Balthasar, 1934

Geiser, Elisabeth, 2023, Revision of the Palaearctic species of the genus Plateumaris C. G. Thomson, 1859 (Coleoptera, Chrysomelidae, Donaciinae), ZooKeys 1177, pp. 167-233 : 167

Plateumaris tenuicornis Balthasar, 1934 syn. nov.

Fig. 6

Type locality.

Bosnia-Hercegovina: Dol. Tuzla, Bosnia.

Type material.

Holotype of Plateumaris tenuicornis . Bosnia-Herzegovina • 1 ex.; Bosnia, Dol. [Dolina?] Tuzla; Em. Fritsch leg.; SNMC. Fig. 6A, B . I examined the holotype in 2020 and it is the only specimen known.

Remarks.

Balthasar (1934) described a species Plateumaris tenuicornis from one P. consimilis specimen collected in Bosnia, which he studied in the collection of the Slovak National Museum, Bratislava. The sketches where he compared the pronotum of both species are provided in Fig. 6C, D . Bechyné (1942) published an article about this description. He studied 335 specimens of P. consimilis , mostly from the area which belongs now to the Czech Republic, but also from central France and Podolia, a historic region in Eastern Europe located in the west-central and south-western parts of Ukraine and north-eastern Moldova, but he did not study the holotype of P. tenuicornis (possibly due to the political situation in Europe at that time). He meticulously worked out that all described characters of P. tenuicornis were within the variation range of the characters of P. consimilis . Bechyné published this article in Czech and Latin in a Czech journal, which has been ignored by most Donaciinae specialists. The English translation of the Latin text is now available in Geiser and Geiser (2023).

Askevold (1991) knew neither of the article of Bechyné (1942) nor of the holotype of P. tenuicornis , but he studied the description of Balthasar (1934) and concluded "All character states used by Balthasar are ones that I have also found among P. consimilis " and then declared P. tenuicornis as a probable new synonym. I studied the holotype of P. tenuicornis still stored in the Slovak National Museum in Bratislava (Fig. 6A, B ) and I can confirm that Bechyné and Askevold were correct in every detail.

Because Bechyné only indirectly treated P. tenuicornis as a synonym, and because Askevold only suggested that P. tenuicornis should be considered as a probable new synonym, I determined that P. tenuicornis Balthasar, 1934 is a new synonym of P. consimilis (Schrank, 1781) according to Bechyné (1942), supposed by Askevold (1991), and now confirmed based on a study of the type material and original descriptions.

Figures

Figure 6. Plateumaris tenuicornis Holotype A habitus B labels of Holotype (photographs by M. Secansky), comparison of the pronotum of C P. tenuicornis with D P. consimilis (from the original description of P. tenuicornis by Balthasar 1934: 128). Scale bars: 2.5 mm.