Protoribates chistyakovi, Ermilov, Sergey G. & Starý, Josef, 2017

Ermilov, Sergey G. & Starý, Josef, 2017, New Protoribates (Acari, Oribatida, Haplozetidae) from Vietnam, Zootaxa 4258 (6), pp. 501-524 : 502-509

Protoribates chistyakovi sp. nov.

( Figs 1–14 )

Diagnosis. Body size: 630–680 × 431–498. Rostral, lamellar and interlamellar setae long, setiform, barbed, in specifically curved mediodistally. Bothridial setae long, setiform, ciliate. Notogastral setae minute. Distance between porose areas A1–A1 shorter than A2–A2. Subcapitular setae h longest, m shortest and thinnest. Epimeral setal formula: 3–1–3–3; setae 3с longest. Circumpedal carinae short. Adanal setae ad 1 and ad 2 of medium size, thickened. Legs tridactylous. Femora II undulate ventroanteriorly. Trochanters IV with two or three teeth dorsoanteriorly. Setae l’ on femora I, II and d on femora III and some ventral setae on tarsi thick.

Description. Measurements. Body length: 680 (holotype, female), 630, 680 (two paratypes: two females); notogaster width: 498 (holotype), 431, 498 (two paratypes).

Integument. Body color brown. Body surface (including genital and anal plates, subcapitular mentum and genae and leg segments) densely microporose (visible under high magnification, ×1000). Macrofoveolae absent. Lateral parts of prodorsum between sublamellae and acetabula I, II microgranulate. Femora II distinctly striate antiaxially.

Prodorsum ( Figs 1 , 3 ). Rostrum broadly rounded. Lamellae (lam) located dorso-laterally, half as long as prodorsum (measured in lateral view). Prolamellae absent. Sublamellae (slam) about half as long as lamellae. Sublamellar porose areas (Al) oval (16–20 × 10–12), located very near to sublamellae. Rostral (ro, 61–69), lamellar (le, 102–114) and interlamellar (in, 123–131) setae setiform, barbed, le inserted on the lamellar ends, in specifically curved mediodistally. Exobothridial setae (ex, 16) thin, slightly barbed. Bothridial setae (bs, 155–159) setiform, ciliate. Sejugal porose areas band-like, diffuse. Tutoria (tu) ridge-like, straight. Lateral ridges (r) present, thin.

Notogaster ( Figs 1 , 3–5 ). Anterior notogastral margin convex medially. Dorsophragmata (D) 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 (16) larger than A1, A2, A3 (10– 12). Distance A1–A1 shorter than A2–A2. Setae lp inserted posteriorly or posteromedially to A1, setae h 3 inserted far anteriorly to A2. Lyrifissures (ia, im, ip, ih, ips) and opisthonotal gland openings (gla) clearly visible, ip located posteriorly to A3.

Gnathosoma ( Figs 6–8 ). Subcapitulum longer than wide (151–155 × 106–114). Subcapitular setae setiform, h longest (45–49), barbed, a (24–28) barbed mediodistally, m shortest (12–16), slightly barbed, thinnest. Two pairs of adoral setae (or 1, or 2, 20) setiform, heavily barbed. Palps (length 94–98) with setation 0–2–1–3–9(+ω). Postpalpal setae (ep, 6) spiniform. Chelicerae (length 164–172) with two barbed setae, cha (53–57) longer than chb (28–32). Trägårdh’s organ (Tg) long, tapered.

Epimeral and lateral podosomal regions ( Figs 2 , 3 ). Epimeral setal formula: 3–1–3–3. Setae setiform, thin, slightly barbed, 3с (45–49) longer than 1b (28–32) and others (14–16). Pedotecta I (Pd I) and II (Pd II) lamina-like, Pd II represented by two connected parts, trapezoid in ventral view, rounded anteriorly. Discidia (dis) triangular, broadly rounded. Custodia absent. Circumpedal carinae (cp) short, directed to acetabula IV.

Anogenital region ( Figs 2–5 , 9 ). Five pairs of genital (g 1, 20; g 2, 16; g 3– g 5, 12–14), one pair of aggenital (ag, 14–16), two pairs of anal (an 1, an 2, 32–36) setae and adanal setae ad 3 (28–32) setiform, slightly barbed. Adanal setae ad 1 and ad 2 of medium size, similar in length (61–69), thickened, erect, barbed. Setae ad 3 inserted anterior to anterior margin of anal aperture. Adanal lyrifissures (iad) located close and parallel to anal plates. Marginoventral porose area (Amar) semioval, interrupted posteromedially. Ovipositor elongated (245 × 36), blades (102) shorter than length of distal section (beyond middle fold; 143). 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 10–14 ). Tridactylous, median claw thicker than laterals, all barbed dorsally. Tibiae I and II with one tubercle ventrobasally. Trochanters IV with two (rarely three) teeth dorsoanteriorly. Femora II undulate ventroanteriorly. Dorsoparaxial porose areas (p.a.) 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 (ɛ) short, thin, straight, indistinctly dilated and truncated distally, inserted posteriorly to ω2. Setae l’ on femora I, II and d on femora III and some ventral setae on tarsi thick.

Roman letters refer to normal setae, Greek letters to solenidia (except ɛ = famulus). Single prime (’) marks setae on the anterior and double prime (”) setae on the posterior side of a given leg segment. Parentheses refer to a pair of setae. Trtrochanter, Fe—femur, Ge—genu, Ti—Tibia, Ta—tarsus.

*—s on tarsi IV absent in P. shvanderovi sp. nov.

Material examined. Holotype (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) . One paratype (one female): Northern Vietnam, Tam Dao National Park, 930 m a.s.l., sample (No. VIE-129) of decaying grass on the soil surface from batata field, 17.X.1988 (collected by J. Starý & Nguen Tri Tien) . One paratype (one female): Northern Vietnam, Tam Dao National Park, 1150 m a.s.l., secondary submontane foggy forest, leaf litter sample (No. VIE-193), 20.X.1988 (collected by J. Starý & Nguen Tri Tien) .

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

Etymology. The species epithet honors Dr. Mikhail P. Chistyakov (1937–2006)—acarologist from Nizhniy Novgorod, Russia—on the 80th anniversary of his birth.

Remarks. Protoribates chistyakovi sp. nov. is morphologically most similar to P. sangumburiensis ( Choi, 1996) from Korea in having setiform bothridial setae, long prodorsal setae and adanal setae ad 1 and ad 2 and tridactylous legs. However, the new species differs from the latter by the larger body size (630–680 × 431–498 vs. 532–592 × 280–320), localization of lamellar setae on lamellar ends (vs. on prodorsum, medially to lamellar ends), broadly rounded rostrum (vs. clearly protruding), thin and rather short epimeral setae 1b (vs. thick and comparatively long) and curved interlamellar setae in medio-distal parts (vs. straight, not curved).

Figures

FIGURE 1. Protoribates chistyakovi sp. nov., adult: dorsal view. Scale bar 100 µm.

FIGURE 2. Protoribates chistyakovi sp. nov., adult: ventral view (gnathosoma and legs not shown). Scale bar 100 µm.

FIGURES 3 – 5. Protoribates chistyakovi sp. nov., adult: 3 — anterior part of body, lateral view (gnathosoma and legs not shown); 4 — posterior part of body, lateral view; 5 — posterior view (part of left half not shown). Scale bar 100 µm.

FIGURES 6 – 9. Protoribates chistyakovi sp. nov., adult: 6 — subcapitulum, ventral view; 7 — palp, right, antiaxial view; 8 — chelicera, right, antiaxial view; 9 — ovipositor (basal part and one blade not shown). Scale bar 50 µm.

FIGURES 10 – 11. Protoribates chistyakovi sp. nov., adult: 10 — leg I, left, paraxial view; 11 — genu, femur and part of trochanter of leg II, right, antiaxial view. Scale bar 50 µm.

FIGURES 12 – 14. Protoribates chistyakovi sp. nov., adult: 12 — tarsus of leg II, right, antiaxial view; 13 — genu, femur and trochanter of leg III, left, antiaxial view; 14 — leg IV, left, antiaxial view. Scale bar 50 µm.