Pilobatella mikoi, Ermilov & Starý, 2020

Ermilov, Sergey G. & Starý, Josef, 2020, Contribution to the knowledge of the oribatid mite genus Pilobatella (Acari, Oribatida, Haplozetidae), Acarologia 60 (3), pp. 545-556 : 547-549

Pilobatella mikoi n. sp.

Zoobank: CF211652-7361-41B6-85EB-3AA2938197B5

( Figures 1–3 )

Diagnosis — Body size 547–647 × 282–348. Rostral, lamellar and interlamellar setae long, setiform, barbed, ro shortest, in longest. Bothridial seta long, gradually thickening distally, beginning at mid-length, ciliate. Tutorium of medium length. All notogastral setae short, setiform, smooth. Epimeral, six pairs of genital and aggenital setae short, setiform, roughened. Medial end of each apodeme 2 close to midline. Anal and adanal setae setiform, erect, densely barbed, ad 1 and ad 2 long. All legs monodactylous. Trochanter IV pointed anterodorsally.

Description — Measurements – Body length 630 (holotype), 547–647 (seven paratypes); body width 348 (holotype), 282–348 (seven paratypes). Females larger than males: 630–647 × 315–348 versus 547–597 × 282–298.

Integument – Body light brown to dark brown. Surface of body and all legs microporose (visible under high magnification, ×1000). Antiaxial side of femur II and paraxial side of femora III and IV striate.

Prodorsum ( Figs 1a, 1c ) – Rostrum rounded. Lamella about 1/2 length of prodorsum, strong. Prolamella absent. Sublamella about 1/3 length of lamella. Sublamellar porose area (16–20 × 10–12) oval, located ventral to sublamella. Tutorium of medium size, about 1/2 length of lamella, ridge-like, distinctly not reaching rostral margin. Prodorsal lateral ridge distinct. Rostral (49–57), lamellar (65–77) and interlamellar (86–98) setae setiform, sparsely barbed; le located on lamellar end. Bothridial seta (94–98) long, narrow proximally, gradually dilating in distal half to narrow head, with short cilia bilaterally. Exobothridial seta (20–28) setiform, thin, slightly barbed. Sejugal porose area not observed.

Notogaster ( Figs 1a, 1c ) – Anterior notogastral margin slightly convex medially. Pteromorph triangular, rounded laterally, with slightly developed hinge. Ten pairs of notogastral setae (10–12) setiform, thin, smooth. Four pairs of sacculi present, Sa bipyriform, S1-S3 pyriform. Notogastral lyrifissure, opisthonotal gland opening, circumgastric scissure and circumgastric sigillar band distinct.

Gnathosoma ( Figs 1b , 3 c-e) – Subcapitulum size 131–139 × 77–86. Subcapitular setae (a, 20–24; m, 10–12; h, 24–28) setiform, sparsely barbed, m thinnest. Adoral seta (14–16) setiform, densely barbed. Palp (73–82) with typical formula. Postpalpal seta (4) spiniform, smooth. Chelicera (131–139) with two setiform, barbed setae (cha, 45–53; chb, 24–28).

Epimeral and lateral podosomal regions ( Figs 1b, 1c ) – Epimeral setal formula 3–1–3–3. All setae setiform, thin, roughened, 3c (24–28) longer than 4c (16–20), 1b, 3b (12–14) and others (10–12). Medial end of each apodeme 2 close to midline. Pedotectum II bifurcate apically in ventral view. Circumpedal carina long, directed to pedotectum II. Discidium triangular.

Anogenital region ( Figs 1b, 1c ) – Six pairs of genital (8–10) and three pairs of aggenital (8–12) setae setiform, thin, roughened. Two pairs of anal (22–24) and three pairs of adanal ad (1, ad 2, 41–49; ad 3, 14–16) setae setiform, erect, barbed. Adanal setae ad 1 and ad 2 inserted on arcuate ridge. Adanal lyrifissure distinct. Marginal porose area complete, narrowly band-like. Preanal organ goblet-like.

Legs ( Figs 2a, 2b , 3a, 3b ) – Monodactylous. Claw of all tarsi strong, slightly barbed on dorsal side, with tubercle ventrobasally. Claw of tarsi I and II thicker than that of tarsi III and IV. Tibiae I and II with tubercle proximoventrally. Femur II with broadly rounded ledge distoventrally. Trochanter IV pointed distodorsally. Dorsoparaxial porose area on all femora and on trochanters III, IV, and proximoventral porose area on all tarsi and distoventral porose area on all 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. Famulus of tarsus I short, erect, slightly dilated distally, inserted between solenidion ω and seta ft ″. Solenidion ω on tarsi I, ω and ω on tarsus II 2 1 1 2 and σ on genu III bacilliform, other solenidia setiform. Seta pl ′ on tarsus I located dorsally on segment, posterior to seta ft ″. Seta l ″ on genu I inserted on tubercle.

Material examined — Holotype (female) and seven paratypes (three males and four females): Madagascar, Andasibe-Mantadia National Park , evergreen rain forest 18,°49 ′ 36 ″ S, 48°26 ′ 52 ″ E, 550 m a.s.l., Winkler apparatus extraction of sifted leaf litter, 28.I.2014 (sample MAG-290 collected by R. Ravebolun and L. Rabotenoson).

Type deposition — The holotype is deposited in the collection of the Senckenberg Institute, Görlitz, Germany. Seven paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia. Specimens are preserved in ethanol with a drop of glycerol.

Etymology — The species name is dedicated to our friend and colleague, the well-known acarologist Prof. Dr. Ladislav Miko ( Slovakia, Bratislava), for his extensive contributions to our knowledge of oribatid mites.

Remarks — In having long interlamellar setae and adanal setae ad 1 and ad 2, Pilobatella mikoi n. sp. is morphologically most similar to Pilobatella baloghi Mahunka, 2003 from Kenya. It differs from the latter by having monodactylous legs (versus tridactylous legs) and a bothridial seta that is gradually expanded to a narrow head (versus setiform, without head).

Figures

Figure 1 Pilobatella mikoi n. sp., adult: a – dorsal view (legs omitted); b – ventral view (legs omitted); c – lateral view (gnathosoma and legs omitted). Scale bar 50 μm.

Figure 2 Pilobatella mikoi n. sp., adult: a – leg I, right, antiaxial view; b – leg IV, left, antiaxial view. Scale bar 20 μm.

Figure 3 Pilobatella mikoi n. sp., adult: a – leg II, without tarsus, right, antiaxial view; b – leg III, without tarsus, left, antiaxial view; c – subcapitulum, ventral view; d – chelicera, left, paraxial view; e – palp, left, antiaxial view. Scale bar 20 μm (a-d), scale bar 10 μm (e).