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 : 209

ATRACTIDES TAENIOLATUS ( MAGLIO, 1928)

Megapus taeniolatus Maglio, 1928

Syn. to A. legeri (Motaş, 1927) : K. Viets, 1956

Type series: Missing (not preserved in the Maglio collection, Verbania-Pallanza, Benfatti pers. comm.). Locus typicus: torrente in Val Malenco (Alpi Retiche) versante destro presso Chiesa (1000 m asl.) fra i muschi, 27 ottobre, 1927, 1 ovigerous female.

Description. Female (original description, male unknown): idiosoma L 745, W 560 Mm (specimen measured after a long time in conservation liquid; treated with KOH and distilled water); integument dorsally lineated, ventrally striated, L of dorsal lines very variable, 5–100 Mm; coxal area L 370, W 535 Mm; posterior margin of Cx-4 straight, locally slightly concave; I-L-5 with S-1/2 L 90/70 Mm, I-L-6 dL 145 Mm, distally curved, with about 10 ventral hairs; genital plates L, 180 Mm, with relatively large Ac arranged in a curved line; 13 eggs 120 Mm in diameter; gnathosoma vL 162 Mm, chelicera L 262 Mm, claw L 80 Mm; no indications on dL of palp segments; P-2 with a cupuliform ventrodistal protuberance bearing 6–7 very fine denticles; P-4 with dense cover of dorsal hairs, insertions of ventral hairs dividing the ventral margin into three equal sectors, sword seta of P-4 near the distoventral hair.

Discussion: When he described this species, Maglio was not aware that there were several other Atractides species with a lineated dorsal integument. Assuming that he had found a taxon different from all hitherto known Atractides species he proposed a separate subgenus: Taeniomegapus. In a note added in proof, he referred to A. legeri , the description of which had appeared in the meantime; he found no differences to A. taeniolatus , but underlined the necessity of comparing the specimens of both species to define their relative taxonomic status, a procedure no longer possible due to the loss of both types. The original description does not contain any feature of diagnostic value for separating the two species. Presence of a denticulated ventral protrusion on P- 2 in the female is not described from any other species with a lineated dorsal integument. No useful information is available about the shape of I-L-5 and - 6 in A. taeniolatus , but from Maglio’s note one may deduce that he did not find differences comparable to those found by Motaş. There is thus sufficient reason to agree with the synonymization of the two species first proposed by K. Viets (1956).

ATRACTIDES FLUVIATILIS ( SZALAY, 1929)

( FIG. 33A–F )

Megapus nodipalpis fluviatilis Szalay, 1929

Separate species: Angelier et al., 1963

Type series: Missing. Locus typicus: Fluss Garam bei Lekér, 23.VI.1927, 1 ♂. Collecting site of females ( Szalay, 1935b): Garamrudnó (Kom. Bars ) aus dem Fluss Garam leg. Dr E. Dudich am 18.VI.1932, 1 ♂, 3 ♀ .

Material examined: SMF 4974 , Jugoslav. Stobrec 17.8.1934 Viets leg. 1 ♂, 2 ♀. State of conservation: perfect; all mouthparts and I-L separate, male Gsk missing ; SMF KOViets 7071 ♀, 7072 ♂ Israel IES 1375 26.11.1979 .

Description:

General features

SMF 4974

dorsal integument: striated (7/10); muscle attachments: not sclerotized

I-L: I-L-5 S-1 and -2 distanced, with fine, but obtuse tips, I-L-6 slender, curved, basally slightly thickened, with parallel dorsal and ventral margins genital field: Ac in an obtuse triangle excretory pore: smooth; Vgl-1: close (fused?) to Vgl-2

palp: weak sexual dimorphism, P-4 1: 1: 1, sword seta near distoventral hair

Males

SMF 4974 genital field: anterior margin slightly concave, posterior margin indented,

slender, external genital plate border narrow, Ac margins facing neighbouring Ac nearly straight; genital setae: 80 palp: ventrodistal margin of P-2 convexly protruding, with traces of a pair of parallel extensions near distal edge; P-4 1: 1: 1, sword seta strong idiosoma L/W 710/550; glandularia 20 coxal field L 360; Cx-3 W 405; Cx-1 + 2 – I-L-5 dL 222, vL 152, dL/vL 1.46, HA-HC 54, 63, 79, dL/HB 3.52 S-1 L 116, L/ W 11.6, S-2 L 93, L/ W 9.3, interspace 39, L S-1/2 1.25 I-L-6 L 163, HA-HC 25, 21, 23, dL/HB 7.76; L I-L-5/6 1.36 genital field L/W 128/145, Ac-1–3 L 42, 42, 42 gnathosoma –; chelicera L 257, L/H 5.71, bS/claw 2.47

Figures

Figure 33. Atractides fluviatilis, Croatia, SMF 4974. A, ♂ I-L-5 and -6; B, ♀ I-L-5 and -6; C, ♂ gnathosoma and palps lateral view; D, ♀ palp, medial view; E, ♀ genital field; F, ♂ genital field. Scale bars = 100 µm.