Trichoribates novus

Bayartogtokh, B. & Schatz, H., 2008, Trichoribates and Jugatala (Acari: Oribatida: Ceratozetidae) from the Central and Southern Alps, with notes on their distribution, Zootaxa 1948, pp. 1-35 : 13-16

Trichoribates novus (Sellnick, 1928)

(Figs. 7, 8)

Murcia nova Sellnick 1928, p. 11.

Trichoribates novus : Willmann 1931, p. 170, fig. 275; van der Hammen 1952, p. 100; Schweizer 1956, p. 326, fig. 285; Shaldybina 1975, p. 292, fig. 708; Pérez-Iñigo 1993, p. 180; Pavlitshenko 1994, p. 31, fig. 22; Bayartogtokh et al. 2002, p. 13, figs. 34 — 41; Weigmann 2006, p. 390, fig. 208a-d.

Murcia nova : Subías 2004, p. 177; 2008, p. 332.

Diagnosis. Rostrum rounded, with a pair of minute lateral dens; rostral, lamellar and interlamellar setae densely barbed; lamella wide, with broad translamella; lamellar cusp with streng lateral dens, medial dens minute or indistinct; sensillus short, with minutely barbed, club-shaped head; tutorium broad, distally pointed; 11 pairs of notogastral setae medium long, barbed, seta dp present; porose areas oval; epimeral setae lc and adanal setae ad1, ad2 barbed, other ventral setae smooth.

Measurements. (n = 3) Body length 616 – 669 (641) µm; length of notogaster 555 – 608 (583) µm; width of notogaster 456 – 509 (484) µm.

Integument. Body colour dark brown to almost black. With thick cerotegument, roughened by minute granules. Faintly microtuberculate on cuticle of prodorsum, notogaster, ventral plate, leg segments and subcapitular mentum.

Prodorsum (Fig. 7 A–C, E, F). Rostrum rounded, with a pair of minute lateral dens, but without nose-like protuberance. Rostral and lamellar setae similar in length, densely barbed. Interlamellar seta about 1.5 x longer than setae ro and le, barbed, almost reaching tip of rostrum. Lamella wide, with longitudinal striations along outer margin; translamella long and wide; lamellar cusp with strong lateral dens, medial dens usually absent, but sometimes minute dens present (Fig. 7F). Sensillus of medium length, with minutely barbed club-shaped head (Fig. 7C). Bothridium small, with pointed bothridial scale svm as seen in dorsal aspect (Fig. 7A). Tutorium broad, with comparatively long, distally pointed cusp, its proximal part with longitudinal striations (Fig. 7 B, E).

Notogaster (Figs. 7A, 8A, B). Oval, about 1.1 x longer than wide. Anterior margin of notogaster arched anteriad, lenticulus poorly developed. Pteromorph large, curved ventrally, anterior portion protruding markedly anteriad. Eleven pairs of notogastral setae, dp present, all setae long, barbed. Porose areas oval to round, Aa largest, A2 smallest. Lyrifissure im small, but well visible in dorsal or lateral view, ia, ih, ip and ips well visible in lateral or posterior view.

Gnathosoma (Figs. 7D). Subcapitular mentum conspicuously wider than long, without noticeable microtubercles. Hypostomal setae a, h and m of medium length, smooth, attenuated. Structure and setation of palp and chelicera typical for family, as shown in the description of T. scilierensis sp. nov.

Epimeral region (Fig. 7D). Most epimeral setae thin, smooth; setae lb and lc conspicuously longer and thicker than other setae, lc barbed, setal formula 3-1-3-3. Custodium reaching anterior margin of pedotectum II; discidium conspicuously projecting laterally.

Ano-genital region (Figs. 7D, 8A). Anal aperture distinctly larger than genital one, anal and genital plates smooth. All ano-genital setae of medium length, thin, smooth, except adanal setae ad1 and ad2 barbed; setal formula same as in the previous species. Distance between bases of aggenital setae nearly equal to that between adanal setae ad3-ad3. Adanal lyrifissure iad short, situated at same level as anal setae an2, adjacent and parallel to anterolateral margin of anal aperture. Postanal porose area very long, narrow, far longer than distance between bases of adanal setae ad2 (Fig. 8A).

Legs. Most leg setae distinctly barbed, except (p) on tarsi I–IV. Setae l ” on tibiae and genua I–IV heavily barbed, much thicker than other setae. Formula of leg setation (including famulus): I (1-5-3-4-20); II (1-5-3-4-15); III (2-2-1-3-15); IV (1-2-2-3-12); formula of solenidia: I (1-2-2); II (1-1-2); III (1-1-0); IV (0-1-0). Illustration of legs is given by Bayartogtokh et al. (2002).

Material examined. Italy, Provincia di Trento, Monte Bondone, near Viote (1650 m a.s.l., 13 June 1991, two females, one male, leg. H. Schatz).

Remarks. The main character states of the examined specimens agree with those of the specimens studied by Shaldybina (1975), Pavlitshenko (1994), Bayartogtokh et al. (2002) and Weigmann (2006). However, none of those descriptions and drawings show the lateral dens on rostrum, but the specimens examined by us have these lateral dens clearly developed. Moreover, Pavlitshenko (1994) shows distinct medial dens of the lamellar cusps, but our specimens have no or very minute medial dens as illustrated by Shaldybina (1975) and Weigmann (2006).

Distribution. This species is commonly distributed in the Holarctic region. In North America it is known only from Virginia, USA (Marshall et al. 1987), but is common in Europe (Schatz 1983; Karppinen et al. 1987, 1992; Bernini et al. 1995; Luxton 1996; Niedbała & Olszanowski 1997; Subías & Gil-Martín 1997). In Asia it was recorded in Turkey, Caucasus, Siberia, Far East of Russia, Japan, Kazakhstan and Mongolia (Golosova et al. 1983; Karppinen et al. 1986; Fujikawa et al. 1993; Rahimbaeva 1995; Ryabinin & Pankov 1997; Shtanchaeva 2001; Bayartogtokh 2007; Erman et al. 2007).