Dinychus indica, Kontschán, Jenő & Ripka, Géza, 2016

Kontschán, Jenő & Ripka, Géza, 2016, New species of Dinychus Kramer, 1886 from fragments of the former Gondwanaland (Acari: Uropodina: Dinychidae), Zootaxa 4138 (2), pp. 363-372 : 363-366

Dinychus indica sp. nov.

( Figs 1–11 )

Material examined. Holotype. Female. India, Himachal Pradesh, Dalhousie, 1950 m, rotten wood ( Pinus , Rhododendron ). 20 November 1988, S. Vit coll. Paratypes: one female and one male, locality and date as for holotype.

Description. Female. Length of idiosoma 600–610 µm, width 300–320 µm (n=2). Shape oblong, posterior margin rounded, colour reddish brown.

Dorsal idiosoma ( Fig. 1 ). Marginal and dorsal shields completely separated. Dorsal and marginal shields covered by oval pits and bearing smooth needle-like setae (ca 13–16 µm long), except the two pairs of marginally pilose setae (ca 15-16 µm long) close to caudal edge of marginal shield. Some poroids situated close to setae on row J. Posterior platelets with three pairs of marginally pilose setae (ca 12–15 µm long).

Ventral idiosoma ( Fig. 2 ). Surface of sternal shield covered by irregular pits close to anterior margin, other surface of ventral idiosoma ornamented by oval pits. All sternal setae smooth, needle-like and short (ca 7–10 µm), St1 situated at level of anterior margin of coxae II, St2 at level of anterior margin of coxae III, St3 at level of central area of coxae III, St4 at level of anterior margin of coxae IV. Five pairs of ventral setae smooth, needle-like and longer than sternal setae (ca 14–18 µm). Setae ad1 short (ca 10–12 µm) and needle-like, setae ad2 and pa similar in shape and length to ventral setae. One pair of lyriform fissures situated close to St3, and one close to ZV2. Stigmata situated close to coxae III. Prestigmatid part of peritremes with a hook-like apical end and a U-shaped central section, poststigmatid part long and curved dorsally ( Fig. 3 ). Genital shield linguliform, without apical process, apical margin of genital shield smooth. Surface of female genital shield covered by oval pits. Pedofossae absent. Base of tritosternum narrow, vase-like, tritosternal laciniae subdivided into two bulbiform central and two smooth, needle-like lateral branches ( Fig. 4 ).

Gnathosoma ( Fig. 4 ). Corniculi horn-like, internal malae smooth, apically bifurcate and longer than corniculi. Hypostomal setae h1 and h3 long (ca 42–55 µm) and basally serrate, h2 shorter (ca 23–25 µm), but the shape same as in h1 and h3, h4 short (ca 10–12 µm) and apically trifurcated. Apical part of epistome marginally pilose. Ventral part of palp trochanter with one smooth and one marginally serrate seta. Chelicerae not clearly visible, fixed digit longer than movable digit.

Legs ( Figs 5–8 ). All legs with ambulacral claws and smooth and needle-like setae, tibia II and III also bearing marginally serrate setae.

Male. Length of idiosoma 570 µm, width 310 µm (n=1).

Dorsal idiosoma. Ornamentation and chaetotaxy of dorsal shield as for female.

Ventral idiosoma ( Fig. 9 ). Three pairs of sternal setae situated anterior to genital shield, and one pair placed at level of central area of genital shield. Sternal setae smooth, needle-like and ca 15–17 µm long. One pair of lyriform fissures situated close to St2 and one pair of poroids at level of caudal margin of genital shield. Surface of sternal shield covered by numerous oval pits. Surface of ventral shield, and shape and size of ventral setae as in female. Genital shield oval and situated between coxae III and IV.

Larva and nymphs unknown.

Etymology. The name of the new species refers to the subcontinent ( India) where it was collected.

Remarks. The new species belongs to the Dinychus woelkei -group on the basis of the three pairs of pilose setae on posterior platelets ( Hirschmann et al. 1984). Currently only three species are reported from this group, two species ( Dinychus feideri Huţu, 1973 and Dinychus woelkei Hirschmann & Zirngiebl-Nicol, 1969 ) occur in Europe and one species ( Dinychus kurosai Hiramatsu, 1978 ) was collected in Japan ( Hiramatsu 1978) and Korea ( Kontschán et al. 2012). The new species differs from the other species of the species group on the basis of the scutiform, ornamented and anteriorly smooth female genital shield.

Figures

FIGURES 1 – 3. Dinychus indica sp. nov. holotype, female. 1. Body in dorsal view. 2. Body in ventral view. 3. Peritreme.

FIGURES 4 – 9. Dinychus indica sp. nov. holotype, female. 4. Ventral view of gnathosoma, palp and coxae I. 5. Ventral view of leg I. 6. Ventral view of leg II. 7. Ventral view of leg III. 8. Ventral view of leg IV. 9. Intercoxal area of male paratype.

FIGURES 10 – 12. Dinychus chilensis sp. nov. holotype, female. 10. Body in dorsal view. 11. Body in ventral view. 12. Peritreme.