Atractides microcavaticus, Schwoerbel, 1961

Gerecke, Reinhard, 2003, Water mites of the genus Atractides Koch, 1837 (Acari: Parasitengona: Hygrobatidae) in the western Palaearctic region: a revision, Zoological Journal of the Linnean Society 138, pp. 141-378 : 303

ATRACTIDES MICROCAVATICUS SCHWOERBEL, 1961

Syn. to A. nodipalpis Thor, 1899 : syn. nov.

Type series: Holotype ♀ CSM Donauversickerung 11.IX.1960; ATRACTIDES microcavaticus TYPUS. State of conservation: idiosoma intact, right IV-L missing, both I-L, gnathosoma, palps, chelicerae under separate cover, crushed and desiccated.

Material examined: CSM, Beera hyporheisch 11.IX.1960 1 ♂, 1 ♀ .

Discussion: As mentioned by Schwoerbel (1961b) the female type specimen of A. microcavaticus has most character states in common with A. nodipalpis . He considered the following as diagnostic for taxonomic separation: genital plates longer than gonopore, I-L-6 relatively short and thus I-L-5/6 ratio higher, narrower setal interspace. Instead, both the I-L-5/6 ratio (1.45) and setal interspace (36 Mm) are within the range of variability, and even close to the mean values, established for a population of A. nodipalpis from southern Germany. The gonopore of the specimen appears indeed to be rather short, but the relative length of the female gonopore is a variable character not suitable for species discrimination in Atractides , and A. microcavaticus should be considered a junior synonym of A. nodipalpis . The second specimen in CSM labelled as A. microcavaticus , but not mentioned in the literature, is most probably an intersex of A. nodipalpis . A definitive taxonomic assessment is impossible due to poor state of conservation.