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 : 203-204

ATRACTIDES LONGITIBIALIS ( WALTER, 1927)

Megapus nodipalpis longitibialis Walter, 1927 (in Walters & Motaş, 1927)

Atractides fonticolus longitibialis ( Walter, 1927) Biesiadka & Kowalik, 1978

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

Type series: NHMB, Syntypes, ♀ Megapus nodipalpis longitibialis Walter Vercors 22.7.26 coll. Motaş 316; XXVIII/90. State of conservation: idiosoma desiccated, air penetrated to the internal part of legs; gnathosoma with palps separate, laterally . ♀ labelled in the same manner, XXVIII/91. State of conservation: palps separate, laterally, gnathosoma missing. Locus typicus: Fontaine de Merle , Engenières, au pied du Vercors, 22 juillet, 1926 , 11 ♀. Further record in the original description: se trouve aussi en Suisse, without identifying site .

Material examined: [ Refused determinations] SMF 3811 , ♀ Spanien, Zaragoza, Torre de Medina , 28.5.1918 ; SMF 7200 ♀ Italien Vomano Fl. Moretti coll. 24.6.1951 .

Description. Female (type series, male unknown): idiosoma L 1190–1280 Mm, W 980–1100 Mm; integument 10 Mm thick, with fine ventral striation, but strong dorsal lineation; antenniformia fine, L 125 Mm; glandularia maximum diameter 38 Mm; coxae and genital field not clearly visible due to desiccation; dL I-L-5 340, HB 75, setal interspace 15, dL I-L-6, 190 Mm; L/W genital field 210/234 Mm; Ac-1–3 forming a triangle, maximum L 50, 60, 64; genital plates L 215; excretory pore unsclerotized, Vgl-1 separate from Vgl-2; palp measurements given in the original description: P-1–5 dL/H 44/47, 100/78, 112/54, 132/36, 44/15, total L 432 Mm, P-2 with a slight ventrodistal protrusion, sword seta of P-4 near the distoventral hair in NHMB 28/90, but near the proximoventral hair in NHMB 28/91.

Discussion: Some of the measurements provided in the original description (here in parentheses) diverge considerably from my measurements of the syntype from NHMB: genital field L 211 (270), W 234 (300) Mm; I-L-5 dL 280 (340), I-L-6 dL, 197 (214) Mm. This observation, as well as differences between the two specimens preserved at NHMB, suggest the presence of different species within the type series. For this reason, and in view of the poor state of conservation of the syntypes in NHMB, I decided not to designate a lectotype, basing the discussion mainly on the drawings in the original publication. From an analysis of Walter’s figure 15A, we can deduce the following values: palp: P-2 L/H 1.3; I-L-5: dL/vL 1.2; dL/HB 4.5; HA/HB 0.9; HB/HC 0.9; S-1 L/ W 12.0; S-2 L/ W 8.4; L S-1/2 1.2. I-L-6: dL/HB 5.6; HA/HB 1.1. dL I-L-5/6 1.7.

In their joint publication, Walter & Motaş considered the assessment of this taxon as a subspecies of A. nodipalpis a preliminary solution that would require re-examination after the discovery of the male. Due to the lineation of the dorsal integument, I-L-5 with subparallel ventral and dorsal margins, narrow setal interspace, I-L-6 thick and L ratio I-L-5/6> 1.6, A. longitibialis resembles A. fonticolus and A. pennatus . Furthermore, females of all three species have a relatively thick P-2 (L/H 1.3–1.4) with roundish ventrodistal protrusion. Walter’s comment concerning the relatively large dimensions of this segment is not confirmed by my measurements. Regarding A. fonticolus , the only valuable differences provided in the original description are the longer palp segments 2–5. In view of the larger size of palp and I-L, and also due to the slender S-2 sword seta, A. longitibialis agrees with A. pennatus . A difference is found only in the shape of I-L-5 which is relatively more expanded distally in A. pennatus (HA/HB 0.73) than in A. longitibialis (HA/ HB 0.90). Some of the measurements published by Walter exceed the dimensions of A. pennatus (e.g. dL I-L-5 340 Mm, compared with 302 Mm in A. pennatus ) but in the syntype the L of this segment is only 279 Mm. All things considered, there is good reason to synonymize A. longitibialis with A. pennatus . In view of the contradictions between type material and publication, as well as the poor state of the type material, this decision should be verified based on material from the locus typicus.

Since the original description, four additional records have been published, from Spain (K. Viets, 1930) Italy (K. Viets, 1955c) Macedonia ( Schwoerbel, 1963) and Poland (without further explanation described as ‘ A.fonticolus longitibialis ’; Biesiadka & Kowalik, 1978). The specimens from Spain and Italy preserved under this name in SMF obviously do not represent A. longitibialis (in both cases the dorsal integument is finely striated, 7/10 Mm, glandularia not enlarged). K. Viets (1950) recognized the error, referred the Spanish record to A. fonticolus , and ignored the record from Italy in his catalogue (K. Viets, 1956). Schwoerbel’s mention from Macedonia contains only a brief remark on the particularly long I-L-5 and does not include measurement data or a discussion of the eventual similarity to other species; the record from Poland is provided within a faunistic table only.