Protoribates shaldybinae sp. nov.

(Figs 15–24)

Diagnosis. Body size: 647–680 × 415–431. Body surface distinctly foveolate. Rostral, lamellar and interlamellar setae long, setiform, barbed. Bothridial setae long, with heads slightly dilated and barbed unilaterally. Notogastral setae minute. Distance between porose areas A1–A1 similar to A2–A2. Subcapitular setae h longest, m shortest and thinnest. Epimeral setal formula: 3–1–3–2; setae 3с longest, 4c absent. Pedotecta II dentate anteriorly. Custodia developed. Circumpedal carinae long. Adanal setae ad 1 and ad 2 of medium size, thickened. Legs I monodactylous, legs II–IV tridactylous, lateral claws with one ventrodistal tooth. Tarsi I and II with two teeth dorsally. Femora II pointed ventroanteriorly.

Description. Measurements. Body length: 680 (holotype, female), 647–680 (three paratypes: three females); notogaster width: 415 (holotype), 415–431 (three paratypes).

Integument (Figs 15, 16, 18, 19). Body color brown. Body surface (including genital and anal plates, subcapitular mentum and genae and leg segments) densely microporose (visible under high magnification, ×1000) and sparsely macrofoveolate (diameter of foveolae up to 2). Lateral parts of prodorsum between sublamellae and acetabula I, II microgranulate.

Prodorsum (Figs 15, 17). Rostrum broadly rounded. Lamellae located dorso-laterally, half as long as prodorsum (measured in lateral view). Prolamellae absent. Sublamellae about one third of lamellae. Sublamellar porose areas oval (18–24 × 10–12), located near to sublamellae. Rostral (77–82), lamellar (123–127) and interlamellar (155–172) setae setiform, barbed, le inserted on the lamellar ends. Exobothridial setae (36) thin, slightly barbed. Bothridial setae (131–143) with long, barbed unilaterally stalks and heads short, slightly dilated and barbed unilaterally, pointed distally. Sejugal porose areas band-like, diffuse. Tutoria ridge-like, slightly curved mediobasally. Lateral ridges present, thin.

Notogaster (Figs 15, 17–19). Anterior notogastral margin convex medially. Dorsophragmata comparatively short, longitudinally elongated, directed posteromedially. Pteromorphs with distinct hinges. Ten pairs of notogastral setae minute (8), thin, smooth. Four pairs of porose areas rounded, Aa largest (10–12), A1, A2 and A3 small (4–6). Distance A1–A1 similar to A2–A2. Setae lp inserted anteromedially to A1, setae h 3 inserted far anteriorly to A2. Lyrifissures and opisthonotal gland openings clearly visible, ip located posterolaterally to A3.

Gnathosoma. Generally, similar to P. chistyakovi sp. nov. Subcapitulum longer than wide (151–155 × 102– 110). Subcapitular setae setiform, h longest (49–53), barbed, a (20–24) slightly barbed, m shortest (12–16), slightly barbed, thinnest. Two pairs of adoral setae (20) setiform, heavily barbed. Palps (length 94–98) with setation 0–2– 1–3–9(+ω). Postpalpal setae (6) spiniform. Chelicerae (length 168–172) with two barbed setae, cha (61–65) longer than chb (32–36). Trägårdh’s organ long, tapered.

Epimeral and lateral podosomal regions (Figs 16, 17). Epimeral setal formula: 3–1–3–2. Setae 4c and their alveoli absent. Setae setiform, thin, slightly barbed, 3с (41–45) longer than 1b (22–24) and others (12–16). Pedotecta I and II lamina-like, Pd II represented by two connected parts, trapezoid in ventral view, distinctly dentate anteriorly. Custodia present, elongate triangular. Circumpedal carinae long, directed to Pd II.

Anogenital region (Figs 16–19). Five pairs of genital (g 1, 20; g 2– g 5, 16), one pair of aggenital (14–16) and two pairs of anal (32–36) setae and adanal setae ad 3 (24) setiform, slightly barbed. Adanal setae ad 1 (98–110) and ad 2 (82–90) of medium size, thickened, erect, barbed. Setae ad 3 inserted anterior to anterior margin of anal aperture. Adanal lyrifissures located close and parallel to anal plates. Marginoventral porose area semioval, interrupted posteromedially. Ovipositor, generally, similar to P. chistyakovi sp. nov., elongated (221 × 41), blades (90) shorter than length of distal section (beyond middle fold; 131). Each of three blades with four straight, smooth setae; ψ1 = τ1 (36–41) longer than ψ2 = τ a = τ b = τ c (16). Six coronal setae minute (4).

Legs (Figs 20–24). Legs I monodactylous, legs II–IV tridactylous, median claw thicker than laterals, all barbed dorsally. Lateral claws with one ventrodistal tooth. Tarsi I and II with two strong teeth dorsally. Tibiae I and II with one tubercle ventrobasally. Femora II pointed ventroanteriorly. Dorsoparaxial porose areas on femora and trochanters III, IV, posteroventral porose areas on tarsi and anteroventral porose areas on tibiae well visible. Formulas of leg setation and solenidia: I (1–5–3–4–20) [1–2–2], II (1–5–3–4–15) [1–1–2], III (2–3–1–3–15) [1–1– 0], IV (1–2–2–3–12) [0–1–0]; homology of setae and solenidia indicated in Table 1. Solenidia ω1 on tarsi I, ω1 and ω2 on tarsi II and σ on genua III bacilliform, other solenidia setiform. Famuli short, thin, straight, indistinctly dilated and truncated distally, inserted posteriorly to ω2.

Material examined. Holotype (female) and one paratype (female): Northern Vietnam, Tam Dao National Park, 950 m a.s.l., meadow, sample (No. VIE-125) of grass rhizosphere, 17.X.1988 (collected by J. Starý & Nguen Tri Tien). Two paratypes (two females): Northern Vietnam, Tam Dao National Park, 1020 m a.s.l., secondary mixed forest, sample (No. VIE-179) of leaf litter, 19.X.1988 (collected by J. Starý & Nguen Tri Tien).

Type deposition. The holotype is deposited in the collection of the Senckenberg Institute, Görlitz, Germany; three paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.

Etymology. The species is named after the late Dr. Elena S. Shaldybina, the acarologist from Nizhniy Novgorod, Russia, for her significant contribution to our knowledge of oribatid mites.

Remarks. Protoribates shaldybinae sp. nov. is morphologically most similar to P. dentatus (Berlese, 1883) (see Weigmann et al. 1993) from the Holarctic and Oriental regions and Fiji in having bothridial setae with heads slightly dilated unilaterally and pointed distally, long prodorsal setae, custodia and adanal setae ad 1, minute notogastral setae and monodactylous legs I and tridactylous legs II–IV. However, the new species differs from the latter by the macrofoveolate body surface (vs. not macrofoveolate), dentate pedotecta II (vs. not dentate), long adanal setae ad 2 (vs. minute) and dorsal teeth on tarsi I and II (vs. without teeth).