Atractides mitisi, (WALTER, 1944)

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 : 243-246

ATRACTIDES MITISI ( WALTER, 1944)

Megapus mitisi Walter, 1944

Syn. to A. panniculatus (K. Viets, 1925) : syn. nov.

Type series: Missing. Locus typicus: Austria, Mittellauf Ybbs Gsadt Ufersteine 28.9.37 2 ♀

Material examined: SMNH 4978 Atractides mitisi (Walt.) ♀ Österrike Lunz. Bäck. 24.5.1955. Leg. O. Lundblad .

Description. Female (original description, male unknown): idiosoma L/W 960/ 800 mm, integument lineated; coxal field L/W 420/ 600 mm, mediocaudal margin of Cx-1 + 2 convex, with a slightly protruding subepidermal medial tip and apodemes of Cx-2 strongly protruding forming an acute angle; caudal margin Cx-4 straight, obviously with strong border of secondary sclerotization; dL I-L-4 270, I-L-5 265, HA 68, HB 65, I-L-6 200 mm, I-L-5 with nearly parallel dorsal and ventral margins, dL/HB 4.08; S-1 slender, slightly enlarged in its distal half, nearly straight, S-2 basally strongly thickened (maximum W 15 mm) setal interspace 43 mm, L ratio I-L-5/6 1.33, I-L-6 proximally nearly straight, from the centre to the tip strongly curved; genital field L 220, gonopore L 160, genital plate L 150 mm, Ac in an obtuse angle, excretory pore smooth, Vgl-1 not fused to Vgl-2; gnathosoma L 140, chelicera total L 245, palp segments (L/H calculated from Walter’s fig. 59) L P-1 38, P-2 90 (L/H 1.50), P-3 115 (L/H 2.50), P-4 135 (L/H 3.84), P-5 45, total L 378 mm, L ratio P-2/4 0.67, ventral margin of P-2 distally strongly inflated and rounded, with maximum H of 60 mm, ventral margin P-4 1: 2: 1, sword seta inserted slightly proximal to the distoventral hair.

Female from SMNH: idiosoma L/W 1200/900 Mm, integument lineation 3/10 Mm, with lines rather short (30–80 Mm) glandularia diameter 27 Mm, coxal field L 470, Cx-3 W 650, Cx-1 + 2 mL 153, lL 297, W 423 Mm, coxae with extended secondary sclerotization, subcutaneous medial tip of Cx-1 + 2 not protruding over the convex posterior margin of Cx-1 + 2, apodemes of Cx-2 nearly parallel, in extremely acute angle; I-L-5 dL 297, vL, 189, HA–HC 69, 76, 112, S-1 L 145 (L/ W 12.0), S-2105 (L/ W 8.8) interspace 47 Mm; I-L-6 L 216, HA–HC 29, 20, 22 Mm, L/HB 10.8, L ratio I-L-5/6 1.38; genital field with borders of secondary sclerotization anteriorly on pregen and anterolaterally on genital plates, Ac-1–3 L 65, 69, 67 Mm; palp total L 445 Mm, L (L/H) P-1 43 (1.19), P-2 100 (1.49), P-3 116 (2.37), P- 4 148 (3.89), P-5 38 (3.45).

Discussion: The female from SMNH agrees closely with the information available from the original description. The only difference is found in generally larger measurements (a difference which might be still more considerable as Walter’s measurement data have a general error of +20%). Due to the wide setal interspace, Walter compared A. mitisi with A. distans and the three Asiatic species A. gassowskii (Sokolow) , A. odarkensis (Sokolow) and A. gracilis (Sokolow) and found a different arrangement of the Ac (in the compared species, arranged in a weakly curved line). In reality, A. mitisi is more similar to A. panniculatus and A. fissus , and in view of the distal position of the distoventral hair of P-4 and the slender I-L-6 it should be considered a synonym of A. panniculatus . The specimen from SMNH is larger than the Alpine populations of A. panniculatus investigated here both with regard to absolute dimensions, and in the relative setal interspace, a rather variable character in A. panniculatus . As to the shape (L/H ratio) of palp segments, the values for A. mitisi lie between those of A. panniculatus and A. fissus , indicating that this character is of little taxonomic significance.

Apart from Lundblad (1956) three further authors recorded A. mitisi . The females from Wienerwald (K. O. Viets, 1958) and from the Polish Carpathians (Biesiadka, 1973) both differ from the type of A. mitisi in the distance of the distoventral seta of P-4 from the edge of the segment; they probably represent A. fissus . Bader (1975) attributed a single male from his collection in the Swiss National Park to this species, without giving any evidence about diagnostic differences between A. mitisi and A. panniculatus , a species widely distributed in the same area. With a setal interspace of 30 Mm and the distoventral hair inserting closely to the distal edge of P-4, it falls within the range of variation in A. panniculatus .

ATRACTIDES OBLONGUS ( WALTER, 1944)

( FIG. 47A–G )

Megapus oblongus Walter, 1944

Syn. A. longus ( Walter, 1947) : syn. nov.; A. szalayi Motaş & Tanasachi, 1948 : syn. nov.; A. nitraensis Láska, 1959 : syn. nov.; A. cerberus Schwoerbel, 1961 : syn. nov.; A. psammophilus Schwoerbel, 1965 : syn. nov.

Type series: Holotype ♀, NHMB, Megapus oblongus ♀ Walter Ybbs 22.9.1937 Coll. v. Mitis Typus; leg. v. Mitis. Ybbs. Daglesbach 22.9.1937; XIV/79 pasted over: Megapus oblongus Walter Pr. 14 79 Type ♀. State of conservation: perfect, gnathosoma incl. chelicerae isolated, in oblique position, both palps separate, lateral; right I-L separate, lateral.

Material examined: A. longus ( Walter, 1947) type series, see under A. longus ; MMB A. longus ; 962–1 Studen y ¢ p. u Zverovky. Liptovske Hote. 10.9.1954 Leg. Làska 1 ♀, 1269–1 Javorinka-Bèlske Tatry 22.6.1958 1 ♀; type series and material examined of A. nitraensis ; 8 slides from coll. CSM (7/1/0) labelled A. szalayi from collecting sites in Germany (Black Forest: Krummenbach, Schwarza, Zastler) and from Austria (Vorarlberg: Egg).

Description:

General features dorsal integument: striated (8–9/10) muscle attachments: unsclerotized coxal field: anterior edges of individual Cx slightly extending

I-L: I-L-5 sword setae similar in shape, slender, close to each other, with obtuse tips; I-L-6 stout, curved with nearly parallel dorsal and ventral margins, claws well developed genital field: Ac in an obtuse triangle excretory pore: smooth; Vgl-1: fused to Vgl-2

palp: no sexual dimorphism, slender; ventral margins P-2–4 straight, P-4 1: 1: 1, sword seta slender, between ventral hairs

Males

Lecto- and paralectotype of A. longus genital field: anterior margin straight, posterior margin weakly indented, gonopore short, with anterior edge on the level of the posterior part of Ac- 1, flanked by four pairs of hairs and in its posterior third by Ac-3; genital setae: 40

Idiosoma L/W 350–450/230–325 glandularia 20

coxal field L 190–247, Cx-3 W 204–224, Cx-1 + 2 mL 78–100, IL 128–161, W 172–190 Mm

I-L-5 dL 96–121, vL 72–94 dL/vL 1.29–1.33, HA-HC 35, 40, 41 (23, 27, 31), dL/ HB 3.03–3.56

S-1 L 52–68 (L/ W 10.4 –11.3), S-2 48 –63 (L/ W 6.9 –9.0), interspace 7–8, S-1/ S- 2 1.08

I-L-6 L 76–96, HA-HC 26, 22, 22 (19, 16, 17), L/HB 4.36–4.75, L I-L-5/6 1.26 genital field L/W 68–90/72–96, Ac-1–3 L 21, 23, 23

gnathosoma vL 67–94 chelicera L 123–166, L/H 5.35, bS/claw 2.51–2.53

Figures

Figure 47. Atractides oblongus. A, C, holotype ♀ B, ♀ from type series of A. longus; D–F, ♂ from type series of A. longus (= syn. to A. oblongus), NHMB. A, ♀ coxal field; B, ♀ genital field; C, ♀ palp, medial view; D, ♂ palp, medial view; E, ♂ coxal and genital field; F, ♂ I-L-5 and -6; G, ♀ I-L-5 and -6. Scale bars = 100 µm.