Damaeus

Miko, L. & Mourek, J., 2008, Taxonomy of European Damaeidae (Acari: Oribatida) I. Kunstidamaeus Miko, 2006, with comments on Damaeus sensu lato, Zootaxa 1820, pp. 1-26 : 3-4

Proposed generic concept of Damaeus sensu lato

After a detailed study of European species of Damaeus sensu lato, and bearing in mind the above-mentioned trends, the following approach has been chosen (see also Miko, 2006). The genera Damaeus (with subgenera Damaeus sensu stricto, Paradamaeus Bulanova-Zachvatkina, 1957 and Adamaeus Norton, 1977), Epidamaeus Bulanova-Zachvatkina, 1957 and Spatiodamaeus Bulanova-Zachvatkina, 1957 are accepted and characterised (Table 1). Most species as well as supraspecific taxa have been defined on the basis of adult characters, although it is clear that examination of immature morphology may bring some new and useful results as well.

The genus Damaeus is characterised by large body size, form and sculpture of prodorsum, with large and well-developed propodolateral apophyses, rugged surface with distinct ridges and a typical set of three pairs of prodorsal tubercles (Da, Ba, Bp). Subgenera within this genus differ in the degree of setal regressions on genu II and III (see Table 1).

The concept of Spatiodamaeus was narrowed (Miko, 2006) to species with interlamellar setae with form and size similar to that of the sensillus (which we consider to be the autapomorphy of this genus, based on its stability within the species group and the absence in other known Damaeidae ), and arrangements of leg setae to form typical verticils. The genus Spatiodamaeus is probably closely related with Damaeus (they are likely sister groups), because they share e.g. the set of tubercles Da, Ba, Bp and presence of accessory seta Ny2' on tarsi I-IV (see also Norton 1977a). Spatiodamaeus lacks the rugged prodorsal surface present only in large species of Damaeus sensu Miko, 2006 (which may therefore be considered to be an autapomorphy of the genus), is generally smaller in size and has relatively shorter legs.

The genus Epidamaeus (European species of which are distinguished by the absence of the propodolateral apophysis) remains problematic in our view. There are at least three species groups, which differ quite significantly and may eventually be proposed as new supraspecific taxa. This idea is supported by recent findings (Mourek & Miko in press.) that some species of Epidamaeus lack a typical character that is - according to Norton (1979b) - shared by Damaeus sensu lato, Dyobelba Norton, 1978a and Lanibelba Norton, 1979c, i.e. a specialization of the famulus in immatures, being reduced, minute and sunken in a sclerotized “cup”.

One particular set of European species cannot easily be included in any of the mentioned genera. Most of these are quite rare, poorly known and insufficiently described; in part, this is probably because they occur in somewhat specific habitats or microhabitats (caves, alpine zone of mountains, bird nests etc.). They include species currently in Damaeus sensu stricto (eg. D. lengersdorfi , D. nidicola - see Schatz 1983 and Olszanowski et al. 1996), Epidamaeus (eg. E. tecticola , E. tenuipes - see Luxton 1989), and Spatiodamaeus (eg. S. diversipilis , S. tecticola - see Schatz 1983). However, all these species share a set of character states. This was already mentioned in descriptions of some of these species by Willmann (1932, 1936), who recognised similarities in development of propodolateral apophysis.

Thorough study of particular species showed that the character set of this species group could be ranked at the same level as Spatiodamaeus or Epidamaeus , i.e. a new genus could be proposed to include them. Kunst (1971, see also 1968, unpublished) - apparently motivated by remarks of Willmann (1932, 1936) - had proposed the subgenus Apodamaeus for some members of this group. However, the name appeared only in determination keys, with no indication of a species that would be available for type designation. Thus, the taxon was a nomen nudum (see Norton 1977b). We believe that the proposal was correct in principle, but the real size of the taxon is greater than Kunst suspected, including among others all the misplaced species indicated above. Therefore, Miko (2006) proposed Kunstidamaeus , named after Miroslav Kunst, the outstanding Czech acarologist who first recognised the group, and developed a key to supraspecific taxa within Damaeus sensu lato. The present paper provides a more detailed description and diagnosis of the genus and its type species, K. lengersdorfi , including information about immature stages.