Nesioneta ellipsoidalis, Li, 2006

Li, Lihong Tu Shuqiang, 2006, Three New And Four Newly Recorded Species Of Linyphiinae And Micronetinae Spiders (Araneae: Linyphiidae) From Northern Vietnam, Raffles Bulletin of Zoology 54 (1), pp. 103-117 : 109-113

Nesioneta ellipsoidalis , new species

( Figs. 5 , 6 )

Type specimens. – Holotype: male, Tan Linh Village , Son Tay Province, Bavi District, Vietnam (138), 24 Dec.2000 . Paratypes: 6 males and 9 females, Tan Linh Village , Son Tay Province, Bavi District, Vietnam (138), 24 Dec.2000 ; 1 female, Ha Jiang Town , Ha Jiang Province, Vietnam (006), 8 Dec.2000 ; 3 females, Viet Lann Village , Ha Jiang Province, Vietnam (022), 10 Dec.2000 ; 5 females, Viet Lann Village , Ha Jiang Province, Vietnam (023), 10 Dec.2000 ; 1 female, Viet Lann Village , Ha Jiang Province, Vietnam (026), 10 Dec.2000 ; 1 male and 1 female, Viet Lann Village , Ha Jiang Province, Vietnam (032), 10 Dec.2000 ; 6 females, Viet Lann Village , Ha Jiang Province, Vietnam (033), 10 Dec.2000 .

Additional compared material examined. – 1 female of Nesioneta benoiti (van Helsdingen, 1978) ( MZT AA0.584), Seychelles, La Passe Gesthause on yard, coll. M. Saaristo, 11 Jan.1999; 1 male of Nesioneta benoiti (van Helsdingen, 1978) ( MZT AA0.585), Seychelles, Silhouette Anse Lacars-Anse Parates sifting leaves of Dendrobium umbellatum , coll. M. Saaristo, 7 Jan.1999.

Diagnosis. – The male of this new species can be easily distinguished by the special shape of male palpal tibia and the posterior tooth of cymbium ( Figs. 5 A-C), as well as the combined characters of embolic division ( Figs. 5 D-E); female can be identified by the round and protruding epigynum with vase-shaped proximal portion of scape and large oval depression of lateral plates on each side ( Fig. 5F ).

Description of male. – Total length: 1.80. Carapace: 0.80 long, 0.60 wide. Abdomen: 1.10 long, 0.60 wide. Carapace grayish brown with black margin. Eyes subequal, with black surroundings; AER recurved, PER straight, eyes separated by AMEr, ALE and PLE juxtaposed. Chelicerae brown, stridulatory ridges present on ectal side, fang groove with three promarginal teeth, second of which biggest, and three small retromarginal teeth. Sternum darker than carapace. Abdomen dark gray, with a large white chevron. Lengths of legs: I 2.80 (0.73+0.90+0.70+0.47), II 2.46 (0.63+0.80+0.60+0.43), III 1.97 (0.57+0.60+0.47+0.33), IV 2.61 (0.80+0.77+0.67+0.37). Tibia dorsal spines: 2-2-2-2. Tm I: 0.28. Tm IV absent.

Male palp ( Figs. 5 A-C). Patella with long bristle dorsally. Tibia widely depressed dorsal-posteriorly, two tips of retrolateral margin and one dorsal tip of prolateral margin rising into lobes, each carrying hair; another process exists anterior-ventrally, also carrying hair. Tibia with two retrolateral and one prolateral trichobothria. Cymbium normal shape, with tooth-like apophysis posteriorly. Paracymbium as usual shaped for Nesioneta , apical branch ending in flat, translucent blade-shaped apex, strong tooth on outer margin of bottom. Pit-hook on distal part of suprategulum bifurcate, one point, slightly hooked, one truncate. Embolic division ( Figs. 5 D-E): radix large boat-shaped with dorsal bulge and anterior hook as usual, all other elements in planted on basal and curved middle part. Lamella characteristica long and sharp. Terminal apophysis consisted of three parts, anterior one large with many dentate-like projections and point tip, middle one short, plate-shaped and strongly sclerotized with scaled surface, posterior one slightly sclerotized with serrated apex. Embolus ( Figs 5E , 6A ) connected with radix by cylindrical membrane, its main body oval plate-shaped with two small apophyses posteriorly ( Fig. 6A ) and two large apophyses anteriorly, dorsal one long and strongly sclerotized extending forward, ventral one slightly sclerotized with sharp process in the middle and its tip rolling back. Seminal duct traversing in embolus plate and retracing back, embolus proper stout, near base, covered ventrally by sclerotic extension of cylindrical membrane.

Description of female. – Total length: 1.83. Carapace: 0.70 long, 0.55 wide. Abdomen: 1.50 long, 0.73 wide. Lengths of legs: I 2.50 (0.70+0.77+0.60+0.43), II 2.30 (0.67+0.70+0.53+0.40), III 1.90 (0.67+0.43+0.47+0.33), IV 2.44 (0.77+0.73+0.57+0.37). Tibia dorsal spines: 2-2-2-2. Tm I: 0.29. Tm IV absent. Other somatic characters same as male.

Epigynum ( Figs. 5 F-I). Half round and convex in ventral view, enlarged lateral plates forming large oval depressions on each side. Scape “S” shaped folding. Margin of proximal portion parallel originally and widened to broadly rounded posterior margin. Inner scape invisible in ventral view. Distal portion with two wings, translucent, hardly discernable in dorsal view, tip furnished with pit extending outside posterior margin visible in ventral view.

Etymology. – The specific name comes from Latin ellipsoidalis (ellipse) in reference to the shape of the embolus of the male palp.

Remarks. – The new species is similar to Nesioneta benoiti (van Helsdingen, 1978) , which was transferred from genus Meioneta by Saaristo (1995). Comparison of the two species revealed that the differences between them mainly concentrated on embolic division ( Figs. 6 A-B): 1) the different shapes of their dorsal embolic apophyses; 2) the middle process of the ventral embolic apophysis in the new species is long and sharp, while it is short in N. benoiti ; 3) the oval plate-shaped main body of embolus of this new species has two small posterior embolic apophyses, while N. benoiti has only one. Additionally, in this new species, the dentate-like projections on the dorsal surface of anterior terminal apophysis in N. benoiti seem much smaller in central than those along the margin ( Fig. 6C ).

Distribution. – Known only from the type locality.

Figures

Fig. 5. Nesioneta ellipsoidalis, new species: A, left male palp, retrolateral view; B, ditto, prolateral view; C, ditto, ventral view; D, embolic division, ventral view; E, ditto, dorsal view; F, epigynum, ventral view; G, ditto, dorsal view; H, ditto lateral view; I, vulva, dorsal view. Scale bars = 0.1 mm.

Fig. 6. Nesioneta ellipsoidalis, new species: A, embolus, dorsal view. Nesioneta benoiti (van Helsdingen, 1978): B, embolus, dorsal view; C, embolic division, ventral view; D, ditto, dorsal view. Scale bars: A-B = 0.05 mm; C-D = 0.1 mm.