Topobates helveticus, Mahunka, S. & Mahunka-Papp, L., 2009

Mahunka, S. & Mahunka-Papp, L., 2009, Topobates helveticus sp. n. and some other remarkable moss mites from Switzerland (Acari: Oribatida)., Revue suisse de Zoologie 116, pp. 325-336 : 326-329

Topobates helveticus sp. n.

Figs 1-3

MATERIAL EXAMINED: Holotype: VS-11: Switzerland: Valais: Grammont , sifting of mosses, 2000 m; 30.VI.1989; leg. C. Besuchet. - 1 paratype from the same sample . Holotype deposited in MHNG, paratype (1708-PO-05) in HNHM.

Etymology: The species is named after the country of its origin.

Diagnosis: Typical scheloribatoid species. Rostral apex obtuse, lamella, sublamella and prelamella present. Prodorsal setae long and strong, distinctly ciliate. Head of sensillus clavate and foveolate, directed outwards and backwards. Dorsosejugal suture gradually convex. Thirteen pairs of simple, rarely pilose and long notogastral setae, four pairs of small sacculi observable. Epimeral setal formula: 3-1-3-3, anogenital setal formula: 4-1-2-3, all simple, short.

Measurements: Length of body: 464-503 µm, width of body: 295-302 µm.

Description: Prodorsum: Apical part of rostrum triangular, rostral apex obtuse. Whole surface of notogaster finely punctate. Lamellar complex well developed, lamella, sublamella strong, reaching the lamellar setae, prelamella slightly thinner (Fig. I). All prodorsal setae comparatively long, distinctly pilose, their ratio: le = in> ro> ex. Peduncle of sensillus short, curved, its head small, asymmetric, with some very small spicules on its distal margin.

FIGS 1-3

Topobates helveticus sp. n. (1) Body in dorsal view. (2) Body in ventral view. (3) Podosoma in lateral view.

Notogaster: Dorsosejugal suture distinct, convex, pteromorphae small, blade-like. Whole surface finely punctate. Thirteen pairs of simple, distinctly and finely barbed, long notogastral setae and four pairs of small sacculi present, Sa slightly larger than the others.

Lateral part of podosoma: Sublamellar area porosa small. Lateral region under prelamella ornamented with weak polygonal pattern (Fig. 3). Pedotecta 1 narrow.

Ventral parts: Surface of infracapitulum, epimeral and ventral plates nearly smooth. Epimeral fields well framed laterally and medially (Fig. 2). Discidium weakly developed, not protruding. All ventral parts with the usual numbers of setae, i.e. epimeral setal formula: 3-1-3-3, anogenital setal formula 4-1-2-3. Except for setae ad1 and ad2, all others short and simple.

Legs: All legs tridactylous and heterodactylous.

Remarks: The new species is well characterised by the thirteen pairs of very long notogastral setae and by the finely punctate notogastral sculpture. On this ground it stands nearest to T. comatus ( Pérez-Inigo, Herrero & Pérez-Inigo, 1987).

Thus, the currently known European Topobates-fauna comprises eight species. On the basis of their main characters (length of notogastral setae, number of notogastral setae and sculpture of notogaster), they can be arranged into three groups. Weigmann & Miko (1998) compiled an identification key for the previously known species, we here add the two Swiss species T. umbraili and T. helveticus sp. n.

Key to European Topobates species

1a Surface of notogaster granular.................. granifer Grandjean, 1958

1b Surface of notogaster smooth, or finely punctate......................2

2a Twelve pairs of notogastral setae present ............................... carpathicus Weigmann & Miko, 1998

2b Thirteen or fourteen pairs of notogastral setae present.................3

3a Fourteen pairs of notogastral setae and live pairs of sacculi present ....................................... alvaradoi Pérez-Inigo. 1969

3b Thirteen pairs of notogastral setae and four pairs of sacculi present....................4

4a Notogastral setae long, distance between the Insertion of dm and dp about as long as the length of setae dm.............................5

4b Notogastral setae short, distance between the Insertion of dm and dp much longer than the length of setae dm............................6

5a Interlamellar setae very long, reaching far over the rostral cusp. Setae dp much longer than the distance between setae dm and dp ..................... comatus ( Pérez-Inigo, Herrero & Pérez-Inigo, 1987)

5b Interlamellar setae ending far from the rostral cusp. Setae dp shorter than the distance between setae dm and dp................... helveticus sp. n.

6a Sensillus long, reaching lateral margin of pteromorphae ........................................ umbraili (Schweizer, 1956)

6b Sensillus short, not reaching lateral margin of pteromorphae.....................7

7a Notogaster with a semicircular band running parallel to margin of body. Setae c2 shorter than posterior notogastral setae ........................... circumcarinatus Weigmann & Miko, 1998

7 b No semicircular band on notogaster. Setae c2 not shorter than posterior notogastral setae.......................... holsaticus Weigmann, 1969