Wandesia stygophila Szalay, 1944

Sabatino, Antonio Di, Gerecke, Reinhard, Gledhill, Terence & Smit, Harry, 2009, On the taxonomy of water mites (Acari: Hydrachnidia) described from the Palaearctic, part 2: Hydryphantoidea and Lebertioidea, Zootaxa 2266, pp. 1-34 : 16-17

Wandesia stygophila Szalay, 1944

Description: As the type series of W. stygophila is lost, for the diagnosis of this species we are restricted to the information given in the original description ( Szalay 1944). This publication is unfortunately inaccurate (with rather sketchy figures and palp measurements that contradict details given in illustration). Furthermore, not only the deutonymph described under this name is surely an adult of a different species (subgenus Wandesia s.str.), but there is also doubt about the conspecifity of male and female. Such an extreme sexual dimorphism in the shape of Cx-I+II (in the Ƥ posteriorly narrowed to a fine strip and medially pointed, in the 3 broadly rounded, with a sector of subparallel opposite coxa margins) and genital field (in the Ƥ with only one pair of setae and round Ac well separated from each other, in the 3 with 8 pairs of setae and longish Ac leaving small interspaces between them) is highly improbable in the genus. Thus, the following extract of potential diagnostic characters is restricted to the male: Idiosoma L/W 1970/540 (but shrunken in ethanol – possibly distinctly longer); integument smooth; Lateral eyes with dark pigmentation (but not in capsules), median eye not observed; gnathsosoma L/H 140/ca. 98 (in the figure given in oblique position, thus shape and H measurement uncertain); chelicera L 196; palp measurements uncertain (following Szalay P-1-5 L 49, 40, 40, 90, 20, his Fig. 1 shows the palp in an oblique position, but, as is usual in the genus, P-1 shorter than P-2). Medial margin of Cx-I+II in the anterior ¾ concave, forming a gnathosomal bay, in its posterior quarter slightly convex, facing the medial edge of the opposite coxal plate. Suture lines Cx-I/II and Cx-III/IV following Szalay's text not reaching the medial margin, but in his Fig.1 , Cx-III+IV with complete suture line as typical for all species of the subgenus. I-L-6 and II-L-6 distal margin, in addition to several fine setae, bearing on each side of the claw furrow one long, rigid, blunt seta. Leg claws simple, without claw blade and clawlets. Genital field length/width 147/115, with three longish-oval Ac and about 8 setae not inserting on sclerite bars.

Discussion: This species has been frequently cited in numerous papers (see K. Viets 1956, K.O.Viets 1987), but additional information was given only by Motaş et al. (1947) with the record of a further female from Romania (Vallée de la Cerna, Băile Herculane, coll. Chappuis). Also this description is rather incomplete and in part probably wrong. Figure 1 of this paper suggests the presence of setae between Ac-3 and the gonopore, in combination with their complete absence lateral to the Ac. A character state of this type has never been observed in another species of the whole subfamily and would surely give reason to treat this specimen as a representative of a separate taxon distinct from W. stygophila . However, apart from this potential artifact, the shape of Cx-I+II (medial margin straight, not embracing the gnathosomal bay and meeting the opposite plate only with its posterior tip, posterior margin subrectangular) indicates that Motaş et al. dealt with a species different to W. stygophila . It is rather probable that the specimen in question is conspecific with the Romanian material described below - as the description excludes important diagnostic features and the material is lost, a final decision is impossible. Also as the records from Corsica ( E. Angelier 1959) refer to a different species ( Gerecke 1999), W. stygophila still remains a rather doubtful species known only from the type locality at Barátka. The character states that should allow the recognition of the species are (1) smooth integument, (2) medial margins of Cx-I+II anteriorly forming a concave gnathosomal bay, posteriorly rounded, (3) presence of two rigid, slender setae flanking the claw furrow of I/II-L (in all other European species only one seta here, located on the posterior side, except for W. saginata Gerecke, 1991 , bearing three setae on each side), (4) genital field with ca. 8 pairs of setae, Ac at equal distance (in males of many Pseudowandesia Ac-2 closer to Ac-1 than to Ac-3). The taxonomic significance of the presence/ absence of clawlets on leg claws (according to Szalay absent) is difficult to judge in Wandesia . Probably, subapical tiny secondary tips are present in all species (occasionally visible at high magnification under a light microscope as described for W. propinqua , see below, in other cases detected only when observed with scanning microscopy).

Figures

FIGURE 1. Torrenticola laskai sp. nov.; A – E, male; A, venter; B, dorsum; C, right palp laterally; D, capitulum and left palp medially; E, ejaculatory complex, anterior view. F, female, venter.