Cultroribula dentata Willmann, 1950

Bayartogtokh, Badamdorj, 2007, Oribatid mites of the family Astegistidae (Acari: Oribatida) in Mongolia, Zootaxa 1472, pp. 55-68 : 62-64

Cultroribula dentata Willmann, 1950

( Fig. 4 )

Cultroribula dentata Willmann, 1950 , p. 192, fig. 4.

Cultroribula dentata: Hammer, 1952 , p. 43, fig. 63; Sellnick, 1960, p. 97; Krivolutsky, 1962, p. 1894; 1975, p. 183, fig. 377; Marshall et al., 1987, p. 178.

Furcoppia (Mexicoppia) dentata: Subias, 2004 , p. 92.

Diagnosis. Relatively small species; body yellowish-brown in color, covered with thin cerotegument; rostrum with 17 teeth, among them a central tooth slightly larger than lateral teeth; lamellae wide, fused medially; lamellar cusps long and wide, with well-developed lateral and smaller median teeth; rostral and lamellar setae moderately long, with conspicuous barbs; interlamellar setae medium long, smooth; sensilli short, with clubshaped head; tutoria relatively short and narrow, distally pointed; ten pairs of short notogastral setae; five pairs of genital setae.

Measurements. Body length: 308–336 (318) Μm; width of notogaster 206–212 (209) Μm. In total 6 specimens were measured.

Integument. Integument nearly smooth and shiny in reflected light at low magnification, but at high magnification prodorsum, lateral part of podosoma and peripheral regions of ventral plate exhibit minute granulation. Body yellowish-brown in color.

Prodorsum. Rostrum with 17 teeth, among them central tooth slightly larger than lateral teeth; size of lateral teeth of rostrum nearly same. Rostral setae moderately long, with strong barbs. Lamellae wide, fused medially; lamellar cusps nearly as long and wide as basal part of lamellae, with well-developed lateral and smaller median teeth. Lamellar and interlamellar setae nearly same in length, conspicuously longer than ro; setae le with distinct barbs, in smooth. Bothridia large, directed anterolaterad, partly concealed under anterior margin of notogaster. Exobothridial setae short, thin, smooth. Sensilli short, with finely barbed club-shaped head. Tutoria relatively short and narrow, not reaching the insertions of rostral setae, distal tip pointed ( Fig. 4 A, C & D).

Notogaster. Oval, longer than wide, dorsosejugal suture broadly rounded; humeral projections poorly developed. Ten pairs of short, thin, smooth notogastral setae nearly same in length. Lyrifissures im, ih, ips, ip and opisthosomal gland opening well developed; lyrifissure ia not evident ( Fig. 4 A, B & D).

Gnathosoma . Infracapitular mentum nearly as long as wide, without noticeable microtubercles. Hypostomal setae a, m and h medium long, thin, smooth ( Fig. 4 B). Chelicerae narrow, elongate, with a few small teeth. Palp normal for family, palpal setation: 0-2-1-3-8 including solenidion ω.

Epimeral region. Apodemes apo.2, apo. sj, apo.3 and apo.4 well developed, nearly transversely oriented. Epimeral setae medium long, smooth; setal formula: 3-1-3-3. Discidium well developed, projected distally; circumpedal carina well developed ( Fig. 4 B).

Ano-genital region. Anal and genital apertures situated far from each other, anal aperture about 1.5 times larger than other aperture. Genital aperture nearly rounded; genital plates with five pairs of medium long, thin, smooth setae. Aggenital setae thin, smooth, slightly shorter than genital setae. Anal aperture widened posteriorly, conspicuously longer than wide; anal and adanal setae equal in size. Adanal lyrifissure well developed ( Fig. 4 B).

Legs. Tarsi heterotridactylous, median claw conspicuously thicker than lateral claws. Femora of all legs with large porose areas. Setae a ’ and a” of legs I and IV strong, with thick barbs. Setation of legs as in the former species.

Material examined. Six specimens (four females and two males): 15 km SE from District Erdene, Central Province, soils of mountain steppe and litter under birch trees, 47o36’N, 107o58’E, elevation 1470m. a.s.l., 0 4 June 2003, Col. B. Bayartogtokh.

Ecology. The present species inhabits the litter of birch forest and soils of mountain steppe, and prefers mesoxeric habitat.

Distribution. This is a Holarctic species, recorded in North America ( USA and Canada), and North-Eastern and Eastern Europe ( Finland and European part of Russia). However, the present species is relatively rare in Asia, and up to date it is known only from Siberia, China and Mongolia.

Remarks. The features of Mongolian materials correspond well with those of the European materials as described or redescribed by Willmann (1950) and Krivolutsky (1975).

Figures

FIGURE 4. Cultroribula dentata Willmann, 1950. A: Dorsal view; B: Ventral view; C: Anterior part of prodorsum; D: Prodorsum and anterior part of notogaster.