Paradinychus pilosus, Kontschán & Starý, 2011

Kontschán, Jenő & Starý, Josef, 2011, Uropodina species from Vietnam (Acari: Mesostigmata), Zootaxa 2807, pp. 1-28 : 13

Paradinychus pilosus sp. nov.

( Figs 32–36 )

Material examined. Holotype. Male ( HNHM), Vietnam, Da Lat, Cam Ly area, moss sample from a fallen tree trunk in the rain-forest, 0 8 December 1994, S. Mahunka, Gy. Sziráki, and L. Zombori coll. Paratypes. Two males (one in ISB, other one in HNHM). Locality and date same as holotype.

Description. Male. Length of idiosoma 410–420 µm, width 200–210 µm (n=3). Shape oblong.

Dorsal idiosoma ( Fig. 32 ). Marginal and dorsal shields not fused. Dorsal shield ornamented by large, oval pits, setae ca 15–17 µm long, marginally pilose, inserted on bulb-like bases. Pygidial shield almost as wide as dorsal shield, without setae or sculptural pattern. Marginal shield posteriorly covered by alveolar pits, with pilose setae similar to those of dorsal shield. Marginal shield subdivided into six platelets in caudal region, lateral two pairs bearing only one setae, the central pair of platelets bearing two setae ( Fig. 32 ). Setae on caudal platelets similar in shape and length to marginal setae, surface of platelets smooth ( Fig. 33 ). Membranous cuticle between marginal and dorsal shields papillate.

Ventral idiosoma ( Fig. 34 ). Several large, alveolar pits situated near coxae, central region of sternal shield smooth. One large oval depression placed near anterior margin of sternal shield. Sternal setae St1-St5 short (ca 6–9 µm), smooth and needle-like, Stx very short (ca 2–3 µm) and placed on anterior margin of genital shield. St1 situated near anterior margin of sternal depression. St2 at level of central region of coxae II, St3 at level of anterior margin of coxae III, St4 at level of posterior margin of coxae III, St5 at the level of anterior margin of coxae IV. Medial ventral setae smooth and needle-like (ca 12–15), lateral ventral setae marginally pilose and ca 12–13 µm long. Adanal setae similar in shape and length to smooth ventral setae, postanal seta bulbiform. Ventral shield covered by alveolar pits. Stigmata situated between coxae II and III. Peritremes C-shaped. Genital shield circular, placed between coxae III. Base of tritosternum wide, only two smooth branches of tritosternal laciniae visible ( Fig. 42 ).

Gnathosoma ( Fig. 36 ). Corniculi horn-like, internal malae very short and smooth. Hypostomal setae h1 ca 22 µm long, smooth, situated near anterior margins of gnathosoma, h2 similar in shape and length to h1, h3 long (ca 27–28 µm), smooth, h4 ca 12 µm long, with one pair of short lateral branches. Epistome marginally serrate. Fixed digit of chelicera with long, pointed apical part ( Fig. 34 ).

Etymology. The name of the new species refers to the pilose dorsal setae.

Remarks. Berlese (1916) established the genus Paradinychus for the species Paradinychus venusta Berlese, 1916 . Two years later, Berlese (1918) moved it into another genus and presented this species as Polyaspidiella venusta . Later Hirschmann, in his “Gangsystem” moved this species into the genus Uroobovella ( Hirschmann & Zirngiebl-Nicol, 1962) , and Hirschmann (1989) esthablished the venusta -group with other two species ( U. fistulata Hiramatsu, 1982 and U. ornata Hirschmann, 1981 ). Hirschmann (1989) placed Uroobovella sumatrensis (Vitzthum) into this group as well, but this species is known only as deutonymph, so its relationship with the other three species is questionable, hence we leave it in the genus Uroobovella .

The genus Paradinychus differs by several characters from Uroobovella ( Table 3), on the basis of the shape of the idiosoma, presence of pygidial shield and caudal platelets, and absence of pedofossae. We consider Paradinychus as a well-defined genus which is easy to separate from the other similar genera. Paradinychus a valid genus that comprises four species that are distributed in the Holarctic and the Oriental regions. The exact position requires a thorough revision, which is beyond the scope of this work. Hence, we place this genus into the family Urodinychidae until this revision is made.

Paradinychus Uroobovella

Type species Paradinychus venusta Berlese Uroobovella obovata Canestrini & Berlese Shape of idiosoma oblong oval

Pygidial shield present absent

Caudal platelets on dorsal idiosoma present absent

Sternal shield ornamented smooth

Number of sternal setae five pairs eight pairs

Pedofossae absent present

Figures

FIGURES 32 – 36. Paradinychus pilosus sp. nov., male. 32, dorsal view; 33, caudal region of dorsal idiosoma; 34, ventral view; 35, peritreme; 36, ventral view of gnathosoma, coxae I and tritosternum. (scale bar: a: 100 μm, b: 50 μm).

FIGURES 42 – 44. Uropoda setata sp. nov., female. 42, dorsal view; 43, ventral view; 44, lateral view. (scale bar: 100 μm).