Trachytes vietnamensis, Kontschán & Starý, 2011

Kontschán, Jenő & Starý, Josef, 2011, Uropodina species from Vietnam (Acari: Mesostigmata), Zootaxa 2807, pp. 1-28 : 2-4

Trachytes vietnamensis sp. nov.

( Figs 1–6 )

Material examined. Holotype. Female ( HNHM), Vietnam, Lao Cai Province, Sín Chai, Hoáng Liên N.P. Tram Ton, along and over a rivulet, 1936 m, 22°20.941’N 103°46.197’E, from moss, 12 December 2008, L. Peregovits coll. Paratype. Deutonymph ( ISB). Locality and date same as holotype.

Description. Female. Length of idiosoma 590 μm, width 370 μm (n = 1). Shape of idiosoma pear-like.

Dorsal idiosoma ( Fig. 1 ). Marginal and dorsal shields not fused anteriorly. Pygidial shield small and rounded, placed between the posterior margin of dorsal shield and the anterior margin of postdorsal shield. All setae on dorsal, marginal, and postdorsal shields smooth, needle-like and ca 47–50 μm long. Surface of dorsal idiosoma covered by oval pits.

Ventral idiosoma ( Fig. 2 ). Sternal setae short, smooth, and needle-like. St1 and St2 situated near the anterior margin of genital shield, their length ca 6–7 μm. St3 ca 12–15 μm long, placed at the level of posterior margin of coxae III, St4 ca 40–42 μm long, situated on adgenital platelets, St5 placed near basal margin of genital shield, 10– 12 μm long. Sternal shield without ornamentation, but bears a strongly sclerotised, U-shaped line near the anterior margin. Ventral and inguinal shields not fused laterally, covered by oval pits, and bearing long (35–40 μm) needlelike setae. Setae X5 (38–40 μm) and X4 (14–15 μm) on small platelets situated in membranous cuticle. Adanal setae and postanal setae similar in shape to ventral setae, but shorter (14–15 μm long). Genital shield wide, oblong, with slightly curved anterior margin, its surface covered by reticulate sculptural pattern. Adgenital platelets present. Genital shield situated between coxae III and IV. Peritremes long and straight, situated near coxae III. Tritosternum ( Fig. 3 ) with wide base, tritosternal laciniae subdivided into four branches.

Gnathosoma ( Fig. 3 ). Corniculi horn-like, internal malae apically serrate. Hypostomal setae h1 long (ca 70 μm) and smooth, h2 short (ca 11 μm) and apically serrate, h3 similar to h 1 in shape, ca 37 μm long. Chelicerae not clearly visible. Palp trochanter with two smooth setae. Margin of epistome serrate.

Deutonymph. Length of idiosoma 540 μm, width 310 μm (n = 1). Idiosoma pear-shaped.

Dorsal idiosoma ( Fig. 4 ) with one pronotal, one pygidial and two mesonotal shields. Surface of dorsal shields smooth. All setae on dorsal idiosoma smooth, needle-like, and ca 17–23 μm long. Dorsal shields covered by alveolar pits.

Ventral idiosoma ( Fig. 5 ) with sternal, endopodal, inguinal and ventrianal shields. Sternal setae smooth, very short (5–7 μm), ventral setae placed on membranous cuticle, smooth, 18–24 μm long, adanal setae on ventrianal shield short (7–8 μm) and smooth. Tritosternum ( Fig. 6 ) with wide base, laciniae subdivided into two branches.

Gnathosoma ( Fig. 6 ). Corniculi horn-like, internal malae smooth. Hypostomal setae h1 long (ca 50 μm), smooth, h2 very short (ca 5–6 μm), smooth, h3 similar to h 1 in shape, ca 37 μm long, h4 short (ca 10 μm) and marginally serrate. Margin of epistome serrate. Chelicerae not clearly visible.

Etymology. The name of the new species refers to the country where it was collected.

Remarks. Till now only four species of Trachytes were known with a wide, oblong female genital shield having slightly curved anterior margin, and these are distributed in North America and Central and Western Europe ( Trachytes lamda Berlese, 1904 , Trachytes balazyi WiŠniewski & Hirschmann, 1994 , Trachytes aegrotasimilis Huţu, 2000 , and Trachytes marilynae Huţu, 2000 ). The distinguising differences between the new species and the previously described species are presented in Table 1 .

and Trachytes aegrotasimilis .

Figures

FIGURES 1 – 2. Trachytes vietnamensis sp. nov., female. 1, dorsal view; 2, ventral view. (scale bar: 100 μm).

FIGURES 3 – 6. Trachytes vietnamensis sp. nov., deutonymph. 3, dorsal view; 4, ventral view; 5, ventral view of gnathosoma of female; 6, ventral view of gnathosoma of deutonymph. (scale bar: 100 μm).