Atractides

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 : 270-271

ATRACTIDES MORAVICUS LÁSKA, 1952

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

Type series: Apparently missing. Locus typicus: Czech Republic, Vsetíner Beskids, potok Jezern y ¢, 23.08.1950 2 ♀ .

Material examined: MMB 493 ; 179-4 Branà v Jindrichové Jeseniky, 18.9.1950 leg. Láska 1 ♀ (together with A. gibberipalpis , 2 ♂, 1 ♀) ; MMB 156 ; 428-1 Divokà Desnà Jeseniky 11.8.1951 leg. Láska 2 ♀ (together with A. nodipalpis 3 ♀) .

Discussion: The fate of the two female specimens on which the first publication of A. moravicus was based ( Láska, 1952) is unclear. In 1964, Láska supplied the description of males based on a specimen from the locus typicus, but the preparation in question is no longer available. The examined specimens as authorized by Láska do not derive from the locus typicus. As far as I know, their collecting sites have not been recorded in a publication. However, they agree with the original description, and one female from MMB 428–1 was used to provide a detailed comparison of measurements.

Láska was convinced of the diagnostic significance of the wide setal interspace, and therefore compared the species with A. distans and A. diastema . It differs from the former in the shape of S-1 (not enlarged distally) and the slightly protruding ventrodistal edge of P-2, and from the latter in the triangular arrangement of the Ac and the position of the sword seta P-4 proximal to the distoventral hair. All these character states are combined in A. nodipalpis . A study on a population of that species reveals considerable variability in the interspace, with maxima exceeding the values in A. moravicus (about 42 Mm). Also, all other measurements fall within the range of variability of A. nodipalpis , except for the slightly more slender I-L-6 (L/HB 10.0) – a negligible detail in view of the extreme variation in this ratio in A. nodipalpis (6.5– 9.6). S-1 (L/ W 14.1) is more slender than in all specimens of the analysed population of A. nodipalpis (8.2–11.7) but its shape is obviously highly variable, and a similarly slender S-1 is found in the neotype of A. nodipalpis .

Judging from Láska’s (1964) description, the shape of I-L-5 and -6 and the genital field of the male attributed to A. moravicus are much the same as typical specimens of A. nodipalpis , although the palp lacks the diagnostic ventral projection of P-2. As pointed out in the section dealing with intersexes, specimens with intersexual character combinations are not infrequently found when larger populations are studied. In fact, both species were collected from the same location. All things considered, there is sufficient evidence for considering A. moravicus to be conspecific with A. nodipalpis .