Tenuiala nuda Ewing, 1913

Zhang, Yan & Jin, Daochao, 2016, Two new species and two newly recorded species of Tenuialidae in China, with an updated key to the family (Acari: Oribatida: Gustavioidea), Zoological Systematics 41 (3), pp. 243-252 : 247-248

Tenuiala nuda Ewing, 1913 New record to China ( Figs 15–19 )

Tenuiala nuda Ewing, 1913: 133–135 , fig.5; Woolley & Higgins, 1955: 46–48, figs 1–2; Norton, 1983: 204; Maruyama & Aoki, 1996: 77–80, figs 1–11.

Diagnosis. Lamellae long and broad, overhunging on lateral contour of prodorsum and separated from each other ( Fig. 15 ). Translamella absent. Sensillus lance-shaped ( Fig. 18 ). Humeral processes long, with a long outer tooth and 1 – 2 minute teeth on anteromedial margins ( Fig. 15 ).

Description. General color a very dark brown. Integument smooth and shiny. Body length 1070–1150; width 940.

Prodorsum ( Figs 15, 17–18 ). Prodorsum steepened at the origin of the cusps. Rostrum emarginate. Rostal setae (63) barbed, shorter than lamellar setae (98). Lamellae long and broad, of equal width throughout their length, overhung lateral contour of prodorsum and separated from each other, without translamella. lamellar setea strongly curved, barbed, and inserted on ventral surface of cusp; interlamellar setae (100) nearly as long as lamellar setae. Sensillus lance-shaped (130). Tutorium distally broad with tooth, curling slightly and dorsally along the both sides.

Notogaster ( Fig. 15 ). Polished and obviously convex, with 10 pairs of alveoli (c, la, lm, lp, h 1, h 2, h 3, p 1, p 2, p 3) and five pairs of lyrifissures (ia, im, in, ips, ip). Humeral processes long, with a long outer tooth and 1-2 minute teeth on anteromedial margins.

Gnathosoma. Subcapitulum diarthric ( Fig. 19 ), longer than wide. Subcapitulum setae setiform, h, m and a 47, 50, and 35 in length respectively. Chelicerae chelate-dentate.

Ventral region ( Fig. 16 ). Third pair of epimeral borders incomplete. Epimeral setal formula: 3-1-3-3. Genital aperture pentagon-shaped, genital plates with 6 pairs of setae, g1 and g2 were longer than g3-g6. 1 pair of aggenital setae present. Anal plates much larger than genital plates, rectangular, with 2 pairs of setae. 3 pair of adanal setae present; lyrifissure iad located posteriad of ad 3, parallel to anal aperture.

Legs. Tridactyle. Chaetotaxy of leg Fe-Ge-Ti-Ta (famulus included, solenidia in parentheses): leg I 5-3(1)-4(2)-20(2); leg II 4-3(1)-4(1)-16(2); leg III 3-2(1)-3(1)-15; leg IV 2-3-3(1)-12.

Material examined. 1 adult, China, Hubei, Triangle Mountain Forest Park (30°29 ′ N, 115°33 ′ E), 12 July 2010, Wenqin Liang ; 1 adult, China, Hubei, Xingdoushan National Nature Reserve (30°14 ′ N, 108°99 ′ E), 4 August, 2010, Wenqin Liang .

Distribution. China (Hubei), Japan, U.S.A.

Remarks. The species was redescribed by Maruyama & Aoki (1996), but nogastral lyrifissures were not mentioned in the description. Nogastral lyrifissures were hereby particularly observed and noted. Except differences in chaetotaxy of leg II and leg III, the feature of the specimens from China agreed well with that by Maruyama & Aoki (1996). Maruyama & Aoki (1996) described 14 setae on tarsus of leg II and 13 setae on tarsus of leg III excluding solenidia and famulus. Tarsus of leg II has 16 setae, and tarsus of leg III 15 setae in the examined specimens.

Figures

Figures 15–19. Tenuiala nuda Ewing 1913. 15. Dorsal view. 16. Ventral view. 17. Prodorsum, dorsal-later view. 18. Sensillus. 19. Subcapitulum, ventral view, right half. Scale bars: 15–17, 19=100 µm, 18=50 µm.