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 : 191

ATRACTIDES QUADRUPORUS ( KOENIKE, 1915)

Megapus quadrupora Koenike, 1915

Species dubia

Type series: Following the type catalogue written by Koenike’s wife (in NHUB) the type preparation was numbered 1770. This slide could not be found neither in NHUB nor in SMNH (where another part of his collection is kept). Locus typicus: Aue bei Leuchtenberg (Prov. Hannover) unweit Bremen Koenike coll. 27.7.1915 .

Description. Male (original description, female unknown): idiosoma nearly round (L 600, W 585 Mm, integument lineated (?-‘deutlich fein gerippt’); gnathosoma with short rostrum (25 Mm); P-4 with interspace between ventral hairs, the proximal one on a protuberance; sword seta near the distoventral hair; distance between Cx-1 + 2 and Cx-3 + 4 larger than in A. ovalis and A. spinipes , apodemes of Cx- 2 in an acute angle with the median line, strongly protruding over the (truncate) posteromedial margin of Cx-1 + 2; I-L-5 and -6 similar in dL (I-L-5 200, I-L-6, 195 Mm); legs without swimming hairs; genital field about 100 Mm from the coxae, L 115, W 130 Mm, anteriorly with a median protrusion, caudally with a median incision, with two pairs of Ac, surrounded by numerous hairs.

Discussion: Koenike did not provide any diagnostic feature that could allow separation from A. gabretae , at that time the only other species with Ac reduced to two pairs (known only from females). According to our present knowledge, in numerous species of the genus a reduced number indicates that an individual is simply misshaped: it cannot serve as a taxonomic character. The original description is based mainly on features common to many, if not all, species of the genus, but the low ratio dL I-L-5/6, and the possibly lineated integument could be a character combination not found in any of the species known at that time. Due to the loss of the type specimen, and also in view of the fact that A. quadruporus was based on a single misshaped individual, it remains a species dubia.

ATRACTIDES GLANDULOSUS ( WALTER, 1918)

( FIG. 25C–K )

Megapus glandulosus Walter, 1918

Type series: Holotype ♂ NHMB Megapus glandulosus Walter ♂ Aare / Aarau, 7.3.1917 coll. Steinmann; Typus; IX/23 (470) idiosoma, state of conservation good, coxae with crash line extending from lateral edge Cx-3/4 to the proximal margin of the gnathosomal bay, left II-L-4–6, III-L-6 missing; ditto IX/24 (470a) gnathosoma, right I-L, both palps separate, desiccated and crushed.

Material examined: NHMB ♀, labelled as holotype, but not part of the type series, with addition Wöschnau ; IX/64 (493) idiosoma, mounting medium largely desiccated, but subject still surrounded by a corona of fluid; IX/65 (493a) gnathosoma, palps (both separate) right I-L, IV-L, left III-L, mounting medium desiccated, subjects surrounded by coronae of fluid . SMF 7998 ♂ Cascade à Tech s/ Tech (Pyr. -or.) 15.VI.1950 [ex coll. Angelier]; 7999 ♀, labelled like 7998 . SMNH 4885 ♀ Schwarzwald , Schönwald, 29.6.1938 ; 4882 ♂ Schwarzwald , Obersimonswald 30.6.1938 .

Refused determination: NHMB [without collecting site identification] Megapus glandulosus ; XXVIII/43 idiosoma, IX/37 (478a) P.S. [collection Piersig] gnathosoma. In view of the different numbers, it is highly doubtful that both preparations refer to the same specimen. Integument structure, as well as shape of mouthparts and I-L differ clearly from A. glandulosus .

Description:

General features dorsal integument: striated (11/10); muscle attachments: unsclerotized glandularia: enlarged by secondary sclerotization

I-L: I-L-5 thickened; I-L-5 S-1 and -2 interspaced, S-1 slender, slightly curved, blunt, S-2 thicker and shorter, pointed, I-L-6 basally thick, distally equally narrowed genital field: Ac in an obtuse triangle excretory pore: smooth; Vgl-1 not fused (in older males closely attached) to Vgl-2

palp: sexual dimorphism

Male

Holotype coxal field: extended secondary sclerotization, including Vgl-3 genital field: anterior margin convex or indented medially, posterior margin indented, Ac-3 longish; genital setae: 50 palp: P-2 slightly protruding ventrodistal protrusion, P-4 2: 1: 1, long ventral hairs, sword seta near the proximoventral hair idiosoma L/W 440/–; glandularia 40 coxal field L 342; Cx-3 W 405; Cx-1 + 2 mL 121, IL 238, W 306 I-L-5 dL 170, vL 128, dL/vL 1.33, HA-HC 65, 69, 72, dL/HB 2.46 S-1 L 92, L/ W 10.2, S-2 L 74, L/ W 6.2, interspace 19, L S-1/2 1.24 I-L-6 L 125, HA-HC 32, 22, 22, dL/HB 5.68; L I-L-5/6 1.36 genital field L/W 117/139, Ac-1–3 L 50, 55, 64 gnathosoma vL 140; chelicera L 211, L/H 5.28, bS/claw 2.35

Figures

Figure 25. A, B, Atractides arcuatus (A. dubius, holotype = syn. to A. arcuatus); A, ♀ palp; B, ♀ I-L-5 and -6 (S-1 and -2 lacking). C–I, Atractides glandulosus. C–E, holotype ♂ NHMB; F–H, paratype ♀ NHMB, I ♂, black forest SMNH 4882, C ♂ coxal field; D, ♂ genital field, E, ♂ I-L-5 and -6; F, ♀ I-L-5 and -6; G, ♀ palp, medial view; H, ♀ genital field and Vgl-1 + 2; I ♂ palp, medial view. Scale bars = 100 µm.