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 : 212

ATRACTIDES SOPRONIENSIS ( SZALAY, 1929)

Megapus soproniensis Szalay, 1929

Atractides (Megapus) nodipalpis soproniensis ( Szalay, 1929) : Szalay, 1956

Atractides fonticolus soproniensis ( Szalay, 1929) : Biesiadka, 1979a

Syn. to A. fonticolus (K. Viets, 1920) : syn. nov.

Type series: Missing. Locus typicus: Sopron, Bach des Tatscher Grabens , 25.VII.1927, 1 ♀ . Collecting site of the male attributed to A. soproniensis by Szalay (1956): Aszófö, Abfluss der Rom-Quelle (32) 11.VII.1932, 1 ♂ (type) 1 ♀ und Csopak, Bach (24) 14.VII.1932, 1 ♀ [D].

Description. Female (original description): idiosoma L/W 984/850 Mm, distance between Dgl-1 233 Mm; coxal field L 400, maximum W 650 Mm, Cx-1 L 300 Mm, with broadly rounded posteromedial margin, apodemes of Cx- 2 in an obtuse angle; I-L-5 dL 241, HB 58, with subparallel dorsal and ventral margins, narrow setal interspace, L S-1 67, S-2 50 Mm, S-2 clearly more enlarged than S-1; I-L-6 dL 133 Mm, weakly curved, not narrowed distally, I-L-5/6 dL ratio 1.81; genital field L/W 217/250, gonopore L 158 Mm, Ac arranged in a triangle; excretory pore unsclerotized, Vgl-1 probably fused to Vgl-2; gnathosoma with short rostrum, palp measurements, P-1–5, L/H 33/40, 83/67, 91/50, 117/33, 33/12, total L 357 Mm, P-2 with a blunt ventrodistal protrusion, sword seta of P-4 approaching distoventral hair.

Male ( Szalay, 1956): idiosoma L/W 745/639 Mm; coxal field L 327, maximum W 491, Cx-1 L 245 Mm; I-L-5 dL 178, HB 47, S-1 L 65, S-2 L 57 Mm, I-L-6 weakly curved, dL 100 Mm (dL I-L-5/6 1.78); genital field with slightly convex, nearly straight anterior, and incised posterior margins, L/W 115/128, gonopore L/W 82/36 Mm, excretory pore unsclerotized, Vgl-1 fused to Vgl-2; gnathosoma with short rostrum, chelicera L 208, claw 73 Mm; palp measurements P-1–5 L/H 32/33, 65/58, 57/40, 84/34, 28/12, total L 266 Mm, P-2 with a relatively strong ventrodistal protrusion, ventrodistal edge of P-3 slightly protruding, P-4 with ventral hairs dividing its ventral margin into three sectors equal in L, medial sword seta inserted halfway between the ventral hairs.

Discussion: In the original description, Szalay stated that A. soproniensis was close to A. vaginalis without providing any diagnostic characters that could separate the two species. There is in fact some similarity to A. vaginalis in the triangular arrangement of the Ac, and I-L-5 with subparallel dorsal and ventral margins. However, the dimensions provided by Szalay surpass much the measurement data of the type of A. vaginalis , the I-L-6 of that species is strongly narrowed distally, and the ventral margin of P- 2 in females is straight. In terms of the shape of the I-L-6, A. soproniensis is more similar to A. adnatus ( Lundblad, 1956) ; however, the latter has a straight ventral margin of P- 2 in both sexes. Later, when he described the male, Szalay (1956) was aware that A. soproniensis is similar to A. fonticolus . As the latter taxon at that time was considered by most authors to be a subspecies of A. nodipalpis , he reduced A. soproniensis to subspecies level as well. Most differences he found between the two taxa concern measurement values only: both sexes of A. fonticolus were found to be smaller than A. soproniensis . Furthermore, the I-L of that species has a relatively shortened terminal segment (I-L-5/6 dL ratio 1.74).

The interpretation of A. soproniensis is hampered due to loss of types and the incomplete description (e.g. no information on integument structure and dimensions of dorsal glandularia). There is full agreement concerning the shape of the genital field in both sexes, and in both taxa the Vgl-1 is fused to Vgl- 2 in males. Furthermore, a slightly protruding distoventral edge of P-3 is also found in A. fonticolus , and the medial sword seta of P-4 can be inserted proximal to the distoventral hair. In this case, there is no reason for interpreting weak differences in measurement values as indicators of taxonomic separation, not even at the subspecies level (as proposed by Biesiadka, 1979a). Therefore A. soproniensis is here synonymized with A. fonticolus .