Nippononeta alpina (Li & Zhu, 1993) Li & Zhu, 1993

Bao, Mengdie, Bai, Zishang & Tu, Lihong, 2017, On a desmitracheate " micronetine " Nippononetaalpina (Li & Zhu, 1993), comb. n. (Araneae, Linyphiidae), ZooKeys 645, pp. 133-146 : 136-137

Nippononeta alpina (Li & Zhu, 1993) comb. n.

Macrargus alpinus Li & Zhu, in Song et al. 1993: 863, f. 21 A–I (D♂♀); Li et al. 1994: 81, f. 31-33 (♀); Li and Zhu 1995: 41, f. 2 a–i (♂♀); Song et al. 1999: 186, f. 104D, G, J (♂♀).

Type material examined.

♂ holotype (IZCAS), China, Hubei Province, Shennongjia Natrual Conservation, Panlong County, 26 June 1986; 1♂ and 2♀ paratypes (IZCAS), same data as the holotype.

Additional material examined.

4♂ and 4♀(CNU), China, Sichuan Province, Lushan County, Fenghuo town, Sanyou village, 7 July 2004, L. Tu leg; 5♂ and 4♀(CNU), China, Sichuan Province, Tianquan County, Mt. Erlangshan Natural Forest Park, 8 July 2004, L. Tu leg; 3♂ and 4♀(CNU), China, Zhejiang Province, Mt. Yandangshan, 28°35.78' N, 121°04.30' E, alt. ca 420m, 15 Aug. 2010, F. Wang leg.

Diagnosis.

The male of Nippononeta alpina comb. n. can be distinguished from all other Nippononeta species by the proximal tibial process (Fig. 2A) and the paracymbial median branch (Fig. 3D), both absent in other Nippononeta species. The female epigynum is distinguished by the epigynal cavity fully filled by the sigmoid folded scape, with a pair of lateral wings on the scape proximal part wrapping downward (Fig. 4A) and another pair of lateral wings on the scape distal part wrapping upward (Fig. 4B), while in most other Nippononeta species the epigynum usually diamond-shaped, with a dorsally opened epigynal cavity and a ventrally exposed scape ( Yan et al. 2015: fig. 2 A–B).

Description.

Chelicerae of normal size, with narrower fang base and denser stridulatory ridges in the male than those in the female (Fig. 5 C–D). Female palp without distal claw (Fig. 4H). Tracheal system having median trunk wider than the lateral pair, highly branched and extending into prosoma (Fig. 4G), tracheoles with taenidia. Epiandrous gland spigots absent in the male (Fig. 4F). Spinnerets (Fig. 4 E–H): PLS in females having the mesal cylindrical gland spigot base enlarged (Fig. 5F), the triplet formed by one flagelliform and two aggregate gland spigots presented in the male PLS (Fig. 5H). For other somatic features, see description for the genus by Eskov (1992).

Male palp (Figs 2 A–F, 3). Tibia short, as long as wide, with three apophyses: one distal, one retrolateral, one proximal; distal tibia apophysis with serrated surface. Cymbium with small retrolateral lobe and proximal fold above paracymbial base. Paracymbium U-shaped, distal arm shorter than proximal one, with well-developed median branch and outer margin fold. Distal suprategular apophysis modified as pit hook with hook sclerite. Embolic membrane furnished with many papillae. Embolic division: boat-shaped radix with ear-like anterior process. Embolus extremely complex, modified with multiple free ends; embolus proper covered by one of embolic sclerites; embolus thumb modified as spine-like projections; and apex triangular; Fickert’s gland located within embolus. Lamella characteristica unbranched, sigmoid ribbon-like in ventral view, with thread-like projections distally. Terminal apophysis divided into two parts: the posterior strongly sclerotized with a rounded end, the anterior membranous part with thread-like projections distally.

Epigynum (Figs 2 G–K, 4 A–E). Epigynal plate protruding out, with wide epigynal basal part. Median plate absent on dorsal surface, but the tegument of epigynal basal part forming transverse dorsal fold. Epigynal cavity fully filled by sigmoid folded scape, covered by a pair of lateral wings on scape proximal part wrapping downward, and another pair of lateral wings on scape distal part wrapping upward; stretcher lifting up. Copulatory tracts in groove state; fertilization tracts changing from groove to duct state and extending towards epigastric furrow.

Remarks.

Nippononeta alpina comb. n. originally was placed in the genus Macrargus Dahl, 1886, whose type species Macrargus rufus Wider, 1834 has a typical haplotracheate system ( Blest 1976). In addition to tracheal characters, the genitalia of Nippononeta alpina are of a different type from that of Macrargus rufus (see descriptions by Saaristo in Marusik and Koponen 2008, Millidge 1977, 1984, Gnelitsa and Koponen 2010). Some genital characters of Nippononeta alpina are consistent with the putative synapomorphies for the genus Nippononeta and for the "desmitracheate micronetines" clade discussed bellow, but not shared by Macrargus rufus .

In addition, Micrargus is masculine in gender, while Nippononeta is feminine. As Macrargus alpinus is being transferred to Nippononeta , the species name has to be changed to alpina . However, Ono and Saito (2001) already described a species also named as Nippononeta alpina Ono & Saito, 2001, which is not a junior synonym of Macrargus alpinus . Therefore we propose a replacement name as onoi, after one author’s name, for the species of Ono and Saito to avoid homonymy.