The taxonomic status of the water mite genera Todothyas Cook and Parathyas Lundblad—supplement to Di Sabatino et al. (2009)

The taxonomic placement of Parathyas Lundblad, 1926 as a separate monotypic genus was questioned by Tuzovskij (2007) who demonstrated the absence of significant apomorphic character states in larvae and arranged the type species in the genus Thyas Koch, 1836. Özdikmen (2006) reported on the homonymy of Thyas Koch, 1836 ["1835", err. Özdikmen] with Thyas Hübner, 1824 (Lepidoptera), and proposed Acerbitas nom. nov. for Thyas Koch, 1836. However, he incorrectly applied the rules of the International Code of Zoological Nomenclature: as stated by Di Sabatino et al. (2009), if this taxon is maintained separate from Parathyas, the first available name for Thyas Koch, 1836 is Todothyas Cook, 1974. Considering that there are no significant differences in larval and adult morphology - dorsal setae on P-4 of adults, for Di Sabatino et al. (2009, p. 4) the main reason to distinguish Parathyas from Todothyas, may also be found in Todothyas bruzelii and T. pachystoma (see Tuzovskij 2007) - there is no evidence to accept the taxonomic placement of the two taxa as separate units.