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 : 330

ATRACTIDES SPINIROSTRIS ( THOR, 1923)

Megapus spinirostris Thor, 1923

Syn. to A. pavesii ( Maglio, 1905) : K. Viets 1955b

Type series: Lost; no holotype designation. Loci typici: Wolga basin: River Twertza near Twer, 21.06.1922, 1 ♀ (prep. 2554) ; River Mologa , 23.06.1922 1 ♂ River Kostroma, 30.06.1922 1 ♂ .

Discussion: The diagnostic characters given by Thor for A. spinirostris concern age-dependent idiosomal proportions such as the relative distance between the coxal field and genital fields, the position of the excretory pore, and the sexual dimorphism of the palp. When comparing the P-3 of his female with Maglio’s description, he was unaware that Maglio had depicted a male. The presence of a smooth, unstriated integument in A. spinirostris is most probably due to age or treatment during preparation. In several A. pavesii - like specimens, as well as in other Atractides species , stages of gradual detachment of the upper integument layer can be observed. Neither the figures nor the measurements published by Thor include any unequivocal information on the identity of this taxon. The presence of A. pavesii , confirmed here as covering an extended area all over Europe including former eastern Prussia ( Russia), suggests that Viets’ proposal to synonymize was correct.

ATRACTIDES LACUSTRIS ( LUNDBLAD, 1925)

( FIG. 86A–H )

Megapus lacustris lacustris Lundblad, 1925

Syn. Atractides lacustris scutatus ( Lundblad, 1925) : Besseling, 1954

Type series: Holotype ♂ SMNH 773 , Megapus lacustris Lundbl. ♂ Småland Björkö socken Stensjön, 1–3 meter leg. O. Lundblad 18.7.1916 773 Typ (249). State of conservation: perfect, both I-L, all right legs, gnathosoma, chelicerae and one palp separate, laterally, one palp dorsally, Gsk separate, anterior . Paratype ♀ SMNH 772 , Megapus lacustris Lundbl. ♀ Småland Nona Uixen leg. O. Lundblad 17.7.1916 772 Allotyp (242). State of conservation: as holotype, but gnathosoma in situ, two eggs.

Description:

General features dorsal integument: striated; muscle attachments: sclerotized, extension of sclerotization variable from isolated knobs to an entire shield covering large parts of the dorsum and including Dgl-3–5; a well sclerotized transverse frontal shield between Dgl-1

coxal field: with extended border of secondary sclerotization, sexual dimorphism

I-L: little modified; setae S-1/2 closely together, S-1 slightly curved inwards, with blunt tip, S-2 with pointed, stiletto-like tip excretory pore: smooth; Vgl-1: fused to Vgl-2

palp: no remarkable sexual dimorphism; P-4 with straight ventral and equally curved dorsal margin, 3: 2: 2, sword seta pointed, between ventral hairs, P-5 without cheeks

Male

Holotype, holotype of A. scutatus :

genital field: with convex, medially protruding border of secondary sclerotization or fused to the caudally extending border of secondary coxal sclerite; genital setae: 42

idiosoma L/W 610/480; glandularia 42

coxal field L 324; Cx-3 W 363; Cx-1 + 2 mL 128, IL 234, W 266

I-L-5 dL 142, vL 114, dL/vL 1.25, HA-HC 29, 34, 38, dL/HB 4.18

S-1 L 44, L/ W 14.7, S-2 L 53, L/ W 13.3, interspace 6, L S-1/2 0.83

I-L-6 L 114, HA-HC 23, 25, 26, dL/HB 4.56; L I-L-5/6 1.25

genital field L/W 114/134, Ac-1–3 L 26, 23, 33

gnathosoma vL 193; chelicera L 277, L/H 9.6, bS/claw 2.79

Figures

Figure 86. A–I Atractides lacustris, A–C, E–H, holotype ♂ SMNH; D, I paratype ♀. SMNH. A, ♂ coxal field; B, ♂ genital and postgenital field, partial view; C, ♂ frontal platelet with Dgl-1/2 and prefrontalia; D, ♀ genital field, E, ♂ I-L-5 and -6; F, ♂ chelicera; G, ♂ palp, medial view; H, ♂ gnathosoma, lateral view (with left P-1 in situ, directed rostrally), I ♀ P-4/5. K, L Atractides ibericus ♀ Gerecke E113. K palp, medial view, L I-L-5 and -6. Scale bars = 100 µm.