Hydrachna cruenta Müller, 1776

Davids, Kees, Sabatino, Antonio Di, Gerecke, Reinhard, Gledhill, Terence & Smit, Harry, 2005, On the taxonomy of water mites (Acari: Hydrachnidia) described from the Palaearctic, part 1: Hydrachnidae, Limnocharidae and Eylaidae, Zootaxa 1061, pp. 36-64 : 40

Hydrachna cruenta Müller, 1776

Hydrachna schneideri Koenike, 1895 : synonymy first proposed by K. Viets (1935) ­ here confirmed.

Material examined: Hydrachna cruenta male SMNH 6043, Östergötland, Källstad socken 13.6.1913 Lundblad; female SMNH 752 Södermanland, Björnhuda, 5.7.1923 Lundblad; Hydrachna schneideri lectotype male, SMNH 375 Heiligenrode, 2370 Ostfriesland.

Discussion: Notwithstanding the lack of type material of H. cruenta , it is generally accepted that the male syntype of H. schneideri Koenike, 1895 is identical to that species. As this specimen must be considered the lectotype of H. schneideri , this name is obviously unavailable in taxonomic nomenclature and the valid name for all specimens published under the name of H. schneideri is H. skorikowi ( Piersig, 1900) (see under this name for a detailed discussion).