Cultroribula vtorovi Krivolutsly, 1971

Bayartogtokh, Badamdorj, 2012, The genus Cultroribula (Acari: Oribatida: Astegistidae) in Mongolia, with new findings from Altai Mountains and remarks on known species of the world, Zootaxa 3302, pp. 44-60 : 51-53

Cultroribula vtorovi Krivolutsly, 1971

(Fig. 5)

Cultroribula vtorovi Krivolutsly, 1971 , p. 940, fig. 2.

Cultroribula vtorovi: Krivolutsly, 1975 , p. 184, fig. 378; Bayartogtokh, 2007, p. 64, fig. 5. Furcoppia (Mexicoppia) vtorovi: Subías, 2004 , p. 92.

Diagnosis. Medium-sized species, covered with thin cerotegument; rostrum with 17 teeth, among them five central teeth much larger than lateral teeth and deeply incised; lamellae wide, fused medially; lamellar cusp long and wide, with large outer and slightly smaller inner teeth; rostral and lamellar setae moderately long, with conspicuous 5. Cultroribula vtorovi Krivolutsky, 1971 . (A) Dorsal view of idiosoma; (B) Ventral view of idiosoma; (C) Rostrum, dorso-frontal view; (D) Lateral view of prodorsum and anterior part of notogaster; (E) Rostral seta; (F) Lamella with cusp and lamellar seta. C–F to same scale.

barbs, interlamellar seta short, thin, smooth; sensillus with short stalk and club-shaped or fusiform head smooth or minutely barbed; tutorium wide at base, with long cusp sharply pointed distally; humeral process of notogaster projected distally or rounded; ten pairs of notogastral setae short; five or six pairs of genital setae, legs tridactylous.

Measurements. Body length: 348–360 (355) μm; width of notogaster 210–220 (216) μm; length of notogaster 259–271 (266) μm. In total three specimens were measured.

Integument. Body yellowish to yellowish-brown in color. Surface of body and leg segments with very thin, nearly smooth cerotegument. Integument microtuberculate on lateral part of prodorsum and around leg acetabula.

Prodorsum. Rostrum with 17 teeth, among them five central teeth much larger than lateral teeth and deeply incised; size of rostral teeth becoming smaller toward posterior direction (Fig. 5C). Rostral seta moderately long, with long barbs (Fig. 5E). Lamella wide, fused medially; lamellar cusp slightly longer, but narrower than basal part of lamella, with large outer and slightly smaller inner teeth. Lamellar seta long, about 1.3 times as long as ro, finely barbed (Fig. 5F). Interlamellar seta short, thin, smooth; bothridium large, with wide opening directed anterolaterad, partly concealed under anterior margin of notogaster (Fig. 5A). Exobothridial seta short, but longer than in, smooth. Sensillus with short stalk and club-shaped or fusiform head smooth or minutely barbed. Tutorium wide at base, with long cusp sharply pointed distally, but not reaching alveolus of rostral seta (Fig. 5D).

Notogaster. Oval, longer than wide, anterior margin almost straight, slightly rounded; humeral process projected distally in both dorsal and lateral views (Fig. 5A & D). Ten pairs of notogastral setae short, thin, smooth, all setae equal in length. Lyrifissures im, ih, ips, ip and opisthonotal gland opening (gla) well developed; lyrifissure ia not evident.

Gnathosoma . Subcapitular mentum nearly as long as wide, with minute microtubercles. Hypostomal setae a, m and h medium long, thin, smooth (Fig. 5B). Chelicera typical for genus as shown in C. altaica sp. nov., with few slightly sclerotized blunt teeth; seta cha barbed, about 1.4 times as long as smooth chb; Trägårdh’s organ well developed, large. Palp typical for genus as in C. altaica sp. nov., palpal setation: 0-2-1-3-8, including solenidion ω of tarsus.

Epimeral region. Apodemes apo.2, apo. sj and apo.3 well developed, slightly obliquely or nearly transversely oriented. Epimeral setae short, smooth; setal formula: 3-1-3-3. Discidium well developed, projecting distally; circumpedal carina well developed, its anterior tectum reaching level of pedotectum II (Fig. 5B).

Ano-genital region. Anal and genital apertures medium in size, situated far from each other. Genital aperture nearly rounded, genital plates with five or six pairs of short, smooth setae. Aggenital seta as long as genital setae, thin, smooth. Anal aperture widened posteriorly, slightly longer than wide; anal and adanal setae short, equal in size. Adanal lyrifissure well developed, situated adjacent to anterolateral corner of anal plate (Fig. 5B).

Legs. Tarsi heterotridactylous, median claw conspicuously thicker than lateral claws. Trochanter and femora of all legs with large porose areas. Setation of legs as in C. altaica sp. nov. Most of tarsal and tibial setae barbed, but those of genua, femora and trochanters mostly smooth. Formula of leg setation (including famulus): I (1-5-3-4-18), II (1-5-2-4-15), III (1-3-1-3-15); IV (1-3-2-3-12); formula of solenidia: I (1-2-2); II (1-1-2); III (1-1-0); IV (0-1-0).

Material examined. Three specimens (two females and one male): Mts. Mongol Altai, close to Lake Dayan, District Sagsai, Province Bayan-Ulgii, litter of cool temperate larch forest ( Larix sibiricus Ledebour, 1833 ), N48o14’, E88o56’, elevation 2358 m a.s.l., 0 4 July 2010, Col. B. Bayartogtokh. All specimens are preserved in alcohol and deposited in the collection of the Department of Zoology, National University of Mongolia.

Remarks. The features of the specimens from Mongolia agree well with those of the specimens from Kyrgyzstan as described by Krivolutsky (1971), and redescribed by Bayartogtokh (2007). The only differences are the relatively shorter interlamellar seta in the present material, more sharply projected humeral process and presence of six pairs of genital setae rather than five pairs in the previously studied specimens. In addition the body size of these specimens was slightly larger than those of the type specimens described by Krivolutsky (1971), and specimens studied previously by me. In my opinion, these are intraspecific variations of different populations of this widely distributed Palaearctic species, which do not merit taxonomic recognition.