Nescina minuta, Ballarin & Li, 2015

Ballarin, Francesco & Li, Shu-Qiang, 2015, Three new genera of the family Nesticidae (Arachnida: Araneae) from Tibet and Yunnan, China, Zoological Systematics 40 (2), pp. 179-190 : 183-189

Nescina minuta sp. nov. ( Figs 3–4 , 7 )

Material examined. Holotype ♂, 20 June 2013, China, Yunnan, Xishuangbanna, Mengla County, Xiaolongha Village ,

Gougu forest, biodiversity protection corridor (21°24'19.3206"N, 101°37'0.5406"E), elev. 808 m, tropical seasonal rain

© Zoological Systematics, 40(2): 179–190

© Zoological Systematics, 40(2): 179–190

view. E. Female habitus, dorsal view. F. Male habitus, lateral view. Scale bars: A–C = 0.1 mm, D–F = 0.5 mm.

© Zoological Systematics, 40(2): 179–190

© Zoological Systematics, 40(2): 179–190

dorsal view. E. Female habitus, dorsal view. F. Female habitus, lateral view. Scale bars: A–C = 0.1 mm, D–F = 0.5 mm.

© Zoological Systematics, 40(2): 179–190 forest, in the litter, sieving, leg. Qing-Yuan Zhao & Zhi-Gang Chen. Paratypes: 1 ♂, 4 ♀, same locality and date as holotype .

Etymology. The name is derived from the Latin word " minutus " meaning "tiny, very little", referring to the very small size of the species, unusual for the Nesticidae ; adjective.

Diagnosis. The male of the new species can be easily separate from the other nesticids by the shape of the terminal apophysis, flat and rounded, and by its small processes ( Figs 3B–D ). The general appearance of the paracymbium, with a hook-like shape and a lobed ventral apophysis, and the laminar process at the base of the conductor ( Figs 3A–B, D ) are also diagnostic characters. Females can be distinguished by the main appearance of the epigyne and especially by the shape of the long, twisted insemination ducts, visible through the tegument. The small size, the dorsal pattern and the presence of 6 small teeth on the promargin of the chelicera can also help to distinguish the species.

Description. Male (holotype). Total length 1.56. Carapace length 0.74, width 0.67. Leg formula: I, IV, II, III. Leg measurements: I: 0.76, 0.21, 0.69, 0.43, 0.34 (2.43); II: 0.56, 0.18, 0.36, 0.34, 0.28 (1.72); III: 0.51, 0.18, 0.36, 0.32, 0.26 (1.63); IV: 0.62, 0.19, 0.53, 0.36, 0.28 (1.98). Habitus as in Figs 4D, F . Prosoma circular in dorsal view, uniformly pale yellow. Fovea visible as a deep depression. Cephalic area elevated and clearly differenced from the rest of the prosoma. Chelicera pale yellow with a row of 6 small teeth on the promargin, the 2 inner larger than the others. Clypeus, labium and sternum of the same color, labium rebordered. Legs uniformly pale yellow. Metatarsal trichobothrium position (TmI) = 0.45. Metatarsus IV with a ventral row of long, serrated bristles (tarsal comb). Opisthosoma oval in dorsal view, uniformly yellow with two or four faint black dots. Ventral side yellow, two fain dark marks at the sides of the spinnerets.

Palp ( Figs 3A–D ) uniformly pale yellow. Cymbium with a long cymbial furrow (Lf) on the retrolateral side. Paracymbium short, transversally oriented to the cymbium, with a hook-like distal process (Dp) bended ventrally and a wide, lobed ventral apophysis (Va). Terminal apophysis (Ta) shaped as a flat and rounded plate with one laminar process frontally oriented (Ta-I) and a small hook-liked process ventrally oriented (Ta-II). Tegular apophysis not visible. Embolus (E) filamentous with a clockwise semicircular course. Conductor (C) laminar, long and flat, starting from the frontal part of the bulb and following the embolus with a counterclockwise course on the prolateral side. A laminar process (Cp-I) is present at its base, near the terminal apophysis.

© Zoological Systematics, 40(2): 179–190

Female (one of the paratypes). Total length: 1.57. Carapace length 0.72, width 0.58. Leg formula: I, IV, II, III . Leg measurements: I: 0.69, 0.22, 0.57, 0.39, 0.41 (2.28); II: 0.59, 0.21, 0.47, 0.35, 0.31 (1.93); III: 0.5, 0.2, 0.35, 0.3, 0.26 (1.61); IV: 0.74, 0.19, 0.47, 0.41, 0.27 (2.08). Habitus as in Fig. 4E . Prosoma oval in dorsal view. Palp with a long claw. The four dots on the dorsal side of the prosoma are more clearly visible than in the male. Color and all the other characters as in the male.

Epigyne and vulva as in Figs 4A–C . Spermathecae (S) and insemination ducts (Id) can be observed through the tegument. Insemination ducts long and twisted, their course is oriented outward and inward at the sides of the copulatory openings, twisting on themselves before reaching the spermathecae. Fertilization ducts (Fd) short and ventrally oriented. Spermathecae large, rounded and close to each other.

Habitat. Litter of tropical seasonal forests.

Distribution. Known only from the type locality.

Figures

Fig. 3. Nescina minuta sp. nov., male palp. A. Dorsal view. B. Ventral view. C. Prolateral view. D. Retrolateral view. Scale bars= 0.1 mm.

Fig. 4. Nescina minuta sp. nov. A. Epigyne, ventral view. B. Vulva, dorsal view. C. Vulva, ventral view. D. Male habitus, dorsal

Fig. 7. Locality records of three new species of the family Nesticidae from China.